diff --git a/docs/hooks.txt b/docs/hooks.txt
index 4fc876c0960..31645ab5dec 100644
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -3921,6 +3921,7 @@ used to alter the SQL query which gets the list of wanted pages.
 [&]$user: user that will watch
 [&]$page: WikiPage object to be watched
 &$status: Status object to be returned if the hook returns false
+$expiry: Optional expiry timestamp in any format acceptable to wfTimestamp()
 
 'WatchArticleComplete': After a watch is added to an article.
 [&]$user: user that watched
diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 165a66e7150..f41e2a98284 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -9095,6 +9095,14 @@ $wgNativeImageLazyLoading = false;
  */
 $wgMainPageIsDomainRoot = false;
 
+/**
+ * Whether to enable the watchlist expiry feature.
+ *
+ * @since 1.35
+ * @var bool
+ */
+$wgWatchlistExpiry = false;
+
 /**
  * For really cool vim folding this needs to be at the end:
  * vim: foldmarker=@{,@} foldmethod=marker
diff --git a/includes/ServiceWiring.php b/includes/ServiceWiring.php
index 94cbff6c944..56eddeb2513 100644
--- a/includes/ServiceWiring.php
+++ b/includes/ServiceWiring.php
@@ -1076,7 +1076,8 @@ return [
 			$services->getReadOnlyMode(),
 			$services->getMainConfig()->get( 'UpdateRowsPerQuery' ),
 			$services->getNamespaceInfo(),
-			$services->getRevisionLookup()
+			$services->getRevisionLookup(),
+			$services->getMainConfig()->get( 'WatchlistExpiry' )
 		);
 		$store->setStatsdDataFactory( $services->getStatsdDataFactory() );
 
diff --git a/includes/actions/WatchAction.php b/includes/actions/WatchAction.php
index e88654ad2fa..a04928716f9 100644
--- a/includes/actions/WatchAction.php
+++ b/includes/actions/WatchAction.php
@@ -111,12 +111,15 @@ class WatchAction extends FormAction {
 	 * @param User $user User who is watching/unwatching
 	 * @param bool $checkRights Passed through to $user->addWatch()
 	 *     Pass User::CHECK_USER_RIGHTS or User::IGNORE_USER_RIGHTS.
+	 * @param string|null $expiry Optional expiry timestamp in any format acceptable to wfTimestamp(),
+	 *   null will not create expiries, or leave them unchanged should they already exist.
 	 * @return Status
 	 */
 	public static function doWatch(
 		Title $title,
 		User $user,
-		$checkRights = User::CHECK_USER_RIGHTS
+		$checkRights = User::CHECK_USER_RIGHTS,
+		?string $expiry = null
 	) {
 		$permissionManager = MediaWikiServices::getInstance()->getPermissionManager();
 		if ( $checkRights && !$permissionManager->userHasRight( $user, 'editmywatchlist' ) ) {
@@ -126,9 +129,9 @@ class WatchAction extends FormAction {
 		$page = WikiPage::factory( $title );
 
 		$status = Status::newFatal( 'hookaborted' );
-		if ( Hooks::run( 'WatchArticle', [ &$user, &$page, &$status ] ) ) {
+		if ( Hooks::run( 'WatchArticle', [ &$user, &$page, &$status, $expiry ] ) ) {
 			$status = Status::newGood();
-			$user->addWatch( $title, $checkRights );
+			$user->addWatch( $title, $checkRights, $expiry );
 			Hooks::run( 'WatchArticleComplete', [ &$user, &$page ] );
 		}
 
diff --git a/includes/user/User.php b/includes/user/User.php
index 34ad0ecb791..31d3b5dc521 100644
--- a/includes/user/User.php
+++ b/includes/user/User.php
@@ -3735,12 +3735,19 @@ class User implements IDBAccessObject, UserIdentity {
 	 * @param Title $title Title of the article to look at
 	 * @param bool $checkRights Whether to check 'viewmywatchlist'/'editmywatchlist' rights.
 	 *     Pass User::CHECK_USER_RIGHTS or User::IGNORE_USER_RIGHTS.
+	 * @param string|null $expiry Optional expiry timestamp in any format acceptable to wfTimestamp(),
+	 *   null will not create expiries, or leave them unchanged should they already exist.
 	 */
-	public function addWatch( $title, $checkRights = self::CHECK_USER_RIGHTS ) {
+	public function addWatch(
+		$title,
+		$checkRights = self::CHECK_USER_RIGHTS,
+		?string $expiry = null
+	) {
 		if ( !$checkRights || $this->isAllowed( 'editmywatchlist' ) ) {
 			MediaWikiServices::getInstance()->getWatchedItemStore()->addWatchBatchForUser(
 				$this,
-				[ $title->getSubjectPage(), $title->getTalkPage() ]
+				[ $title->getSubjectPage(), $title->getTalkPage() ],
+				$expiry
 			);
 		}
 		$this->invalidateCache();
diff --git a/includes/watcheditem/NoWriteWatchedItemStore.php b/includes/watcheditem/NoWriteWatchedItemStore.php
index f4b5e89bd1f..30ee9c06e02 100644
--- a/includes/watcheditem/NoWriteWatchedItemStore.php
+++ b/includes/watcheditem/NoWriteWatchedItemStore.php
@@ -105,11 +105,15 @@ class NoWriteWatchedItemStore implements WatchedItemStoreInterface {
 		throw new DBReadOnlyError( null, self::DB_READONLY_ERROR );
 	}
 
-	public function addWatch( UserIdentity $user, LinkTarget $target ) {
+	public function addWatch( UserIdentity $user, LinkTarget $target, ?string $expiry = null ) {
 		throw new DBReadOnlyError( null, self::DB_READONLY_ERROR );
 	}
 
-	public function addWatchBatchForUser( UserIdentity $user, array $targets ) {
+	public function addWatchBatchForUser(
+		UserIdentity $user,
+		array $targets,
+		?string $expiry = null
+	) {
 		throw new DBReadOnlyError( null, self::DB_READONLY_ERROR );
 	}
 
diff --git a/includes/watcheditem/WatchedItem.php b/includes/watcheditem/WatchedItem.php
index 4bf7f0c3006..fa1372672df 100644
--- a/includes/watcheditem/WatchedItem.php
+++ b/includes/watcheditem/WatchedItem.php
@@ -46,19 +46,27 @@ class WatchedItem {
 	 */
 	private $notificationTimestamp;
 
+	/**
+	 * @var string|null When to automatically unwatch the page
+	 */
+	private $expiry;
+
 	/**
 	 * @param UserIdentity $user
 	 * @param LinkTarget $linkTarget
 	 * @param null|string $notificationTimestamp the value of the wl_notificationtimestamp field
+	 * @param null|string $expiry Optional expiry timestamp in any format acceptable to wfTimestamp()
 	 */
 	public function __construct(
 		UserIdentity $user,
 		LinkTarget $linkTarget,
-		$notificationTimestamp
+		$notificationTimestamp,
+		?string $expiry = null
 	) {
 		$this->user = $user;
 		$this->linkTarget = $linkTarget;
 		$this->notificationTimestamp = $notificationTimestamp;
+		$this->expiry = $expiry;
 	}
 
 	/**
@@ -91,4 +99,31 @@ class WatchedItem {
 	public function getNotificationTimestamp() {
 		return $this->notificationTimestamp;
 	}
+
+	/**
+	 * When the watched item will expire.
+	 *
+	 * @since 1.35
+	 *
+	 * @return string|null null or in a format acceptable to wfTimestamp().
+	 */
+	public function getExpiry(): ?string {
+		return $this->expiry;
+	}
+
+	/**
+	 * Has the watched item expired?
+	 *
+	 * @since 1.35
+	 *
+	 * @return bool
+	 */
+	public function isExpired(): bool {
+		if ( null === $this->getExpiry() ) {
+			return false;
+		}
+
+		$unix = MWTimestamp::convert( TS_UNIX, $this->getExpiry() );
+		return $unix < wfTimestamp();
+	}
 }
diff --git a/includes/watcheditem/WatchedItemStore.php b/includes/watcheditem/WatchedItemStore.php
index 2e5797d421d..10316fc4713 100644
--- a/includes/watcheditem/WatchedItemStore.php
+++ b/includes/watcheditem/WatchedItemStore.php
@@ -7,6 +7,7 @@ use MediaWiki\User\UserIdentity;
 use Wikimedia\Assert\Assert;
 use Wikimedia\Rdbms\IDatabase;
 use Wikimedia\Rdbms\ILBFactory;
+use Wikimedia\Rdbms\IResultWrapper;
 use Wikimedia\Rdbms\LoadBalancer;
 use Wikimedia\ScopedCallback;
 
@@ -89,6 +90,11 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 	 */
 	private $stats;
 
+	/**
+	 * @var bool Correlates to $wgWatchlistExpiry feature flag.
+	 */
+	private $expiryEnabled;
+
 	/**
 	 * @param ILBFactory $lbFactory
 	 * @param JobQueueGroup $queueGroup
@@ -98,6 +104,7 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 	 * @param int $updateRowsPerQuery
 	 * @param NamespaceInfo $nsInfo
 	 * @param RevisionLookup $revisionLookup
+	 * @param bool $expiryEnabled
 	 */
 	public function __construct(
 		ILBFactory $lbFactory,
@@ -107,7 +114,8 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		ReadOnlyMode $readOnlyMode,
 		$updateRowsPerQuery,
 		NamespaceInfo $nsInfo,
-		RevisionLookup $revisionLookup
+		RevisionLookup $revisionLookup,
+		bool $expiryEnabled
 	) {
 		$this->lbFactory = $lbFactory;
 		$this->loadBalancer = $lbFactory->getMainLB();
@@ -121,6 +129,7 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		$this->updateRowsPerQuery = $updateRowsPerQuery;
 		$this->nsInfo = $nsInfo;
 		$this->revisionLookup = $revisionLookup;
+		$this->expiryEnabled = $expiryEnabled;
 
 		$this->latestUpdateCache = new HashBagOStuff( [ 'maxKeys' => 3 ] );
 	}
@@ -216,23 +225,6 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		return $this->cache->get( $this->getCacheKey( $user, $target ) );
 	}
 
-	/**
-	 * Return an array of conditions to select or update the appropriate database
-	 * row.
-	 *
-	 * @param UserIdentity $user
-	 * @param LinkTarget $target
-	 *
-	 * @return array
-	 */
-	private function dbCond( UserIdentity $user, LinkTarget $target ) {
-		return [
-			'wl_user' => $user->getId(),
-			'wl_namespace' => $target->getNamespace(),
-			'wl_title' => $target->getDBkey(),
-		];
-	}
-
 	/**
 	 * @param int $dbIndex DB_MASTER or DB_REPLICA
 	 *
@@ -413,12 +405,32 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		foreach ( $rows as $namespace => $namespaceTitles ) {
 			$rowBatches = array_chunk( $namespaceTitles, $this->updateRowsPerQuery );
 			foreach ( $rowBatches as $toDelete ) {
-				$dbw->delete( 'watchlist', [
+				// First fetch the wl_ids.
+				$wlIds = $dbw->selectField( 'watchlist', 'wl_id', [
 					'wl_user' => $user->getId(),
 					'wl_namespace' => $namespace,
 					'wl_title' => $toDelete
-				], __METHOD__ );
-				$affectedRows += $dbw->affectedRows();
+				] );
+
+				if ( $wlIds ) {
+					// Delete rows from both the watchlist and watchlist_expiry tables.
+					$dbw->delete(
+						'watchlist',
+						[ 'wl_id' => $wlIds ],
+						__METHOD__
+					);
+					$affectedRows += $dbw->affectedRows();
+
+					if ( $this->expiryEnabled ) {
+						$dbw->delete(
+							'watchlist_expiry',
+							[ 'we_item' => $wlIds ],
+							__METHOD__
+						);
+						$affectedRows += $dbw->affectedRows();
+					}
+				}
+
 				if ( $ticket ) {
 					$this->lbFactory->commitAndWaitForReplication( __METHOD__, $ticket );
 				}
@@ -564,7 +576,7 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		}
 
 		$cached = $this->getCached( $user, $target );
-		if ( $cached ) {
+		if ( $cached && !$cached->isExpired() ) {
 			$this->stats->increment( 'WatchedItemStore.getWatchedItem.cached' );
 			return $cached;
 		}
@@ -586,22 +598,19 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 
 		$dbr = $this->getConnectionRef( DB_REPLICA );
 
-		$row = $dbr->selectRow(
-			'watchlist',
-			'wl_notificationtimestamp',
-			$this->dbCond( $user, $target ),
-			__METHOD__
+		$row = $this->fetchWatchedItems(
+			$dbr,
+			$user,
+			[ 'wl_notificationtimestamp' ],
+			[],
+			$target
 		);
 
 		if ( !$row ) {
 			return false;
 		}
 
-		$item = new WatchedItem(
-			$user,
-			$target,
-			$this->getLatestNotificationTimestamp( $row->wl_notificationtimestamp, $user, $target )
-		);
+		$item = $this->getWatchedItemFromRow( $user, $target, $row );
 		$this->cache( $item );
 
 		return $item;
@@ -630,11 +639,10 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		}
 		$db = $this->getConnectionRef( $options['forWrite'] ? DB_MASTER : DB_REPLICA );
 
-		$res = $db->select(
-			'watchlist',
+		$res = $this->fetchWatchedItems(
+			$db,
+			$user,
 			[ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp' ],
-			[ 'wl_user' => $user->getId() ],
-			__METHOD__,
 			$dbOptions
 		);
 
@@ -642,17 +650,86 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		foreach ( $res as $row ) {
 			$target = new TitleValue( (int)$row->wl_namespace, $row->wl_title );
 			// @todo: Should we add these to the process cache?
-			$watchedItems[] = new WatchedItem(
-				$user,
-				$target,
-				$this->getLatestNotificationTimestamp(
-					$row->wl_notificationtimestamp, $user, $target )
-			);
+			$watchedItems[] = $this->getWatchedItemFromRow( $user, $target, $row );
 		}
 
 		return $watchedItems;
 	}
 
+	/**
+	 * Construct a new WatchedItem given a row from watchlist/watchlist_expiry.
+	 * @param UserIdentity $user
+	 * @param LinkTarget $target
+	 * @param stdClass $row
+	 * @return WatchedItem
+	 */
+	private function getWatchedItemFromRow(
+		UserIdentity $user,
+		LinkTarget $target,
+		stdClass $row
+	): WatchedItem {
+		return new WatchedItem(
+			$user,
+			$target,
+			$this->getLatestNotificationTimestamp(
+				$row->wl_notificationtimestamp, $user, $target ),
+			wfTimestampOrNull( TS_MW, $row->we_expiry ?? null )
+		);
+	}
+
+	/**
+	 * Fetches either a single or all watched items for the given user.
+	 * If a $target is given, IDatabase::selectRow() is called, otherwise select().
+	 * If $wgWatchlistExpiry is enabled, expired items are not returned.
+	 *
+	 * @param IDatabase $db
+	 * @param UserIdentity $user
+	 * @param array $vars we_expiry is added when $wgWatchlistExpiry is enabled.
+	 * @param array $options
+	 * @param LinkTarget|null $target null if selecting all watched items.
+	 * @return IResultWrapper|stdClass|false
+	 */
+	private function fetchWatchedItems(
+		IDatabase $db,
+		UserIdentity $user,
+		array $vars,
+		array $options = [],
+		?LinkTarget $target = null
+	) {
+		$dbMethod = 'select';
+		$conds = [ 'wl_user' => $user->getId() ];
+
+		if ( $target ) {
+			$dbMethod = 'selectRow';
+			$conds = array_merge( $conds, [
+				'wl_namespace' => $target->getNamespace(),
+				'wl_title' => $target->getDBkey(),
+			] );
+		}
+
+		if ( $this->expiryEnabled ) {
+			$vars[] = 'we_expiry';
+			$conds[] = 'we_expiry IS NULL OR we_expiry > ' . $db->addQuotes( $db->timestamp() );
+
+			return $db->{$dbMethod}(
+				[ 'watchlist', 'watchlist_expiry' ],
+				$vars,
+				$conds,
+				__METHOD__,
+				$options,
+				[ 'watchlist_expiry' => [ 'LEFT JOIN', [ 'wl_id = we_item' ] ] ]
+			);
+		}
+
+		return $db->{$dbMethod}(
+			'watchlist',
+			$vars,
+			$conds,
+			__METHOD__,
+			$options
+		);
+	}
+
 	/**
 	 * @since 1.27
 	 * @param UserIdentity $user
@@ -718,21 +795,34 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 	}
 
 	/**
-	 * @since 1.27
+	 * @since 1.27 Method added.
+	 * @since 1.35 Accepts $expiry parameter.
 	 * @param UserIdentity $user
 	 * @param LinkTarget $target
+	 * @param string|null $expiry Optional expiry in any format acceptable to wfTimestamp().
+	 *   null will not create an expiry, or leave it unchanged should one already exist.
 	 */
-	public function addWatch( UserIdentity $user, LinkTarget $target ) {
-		$this->addWatchBatchForUser( $user, [ $target ] );
+	public function addWatch( UserIdentity $user, LinkTarget $target, ?string $expiry = null ) {
+		$this->addWatchBatchForUser( $user, [ $target ], $expiry );
 	}
 
 	/**
-	 * @since 1.27
+	 * Add multiple items to the user's watchlist.
+	 * If adding a single item, use self::addWatch() where you can optionally provide an expiry.
+	 *
+	 * @since 1.27 Method added.
+	 * @since 1.35 Accepts $expiry parameter.
 	 * @param UserIdentity $user
 	 * @param LinkTarget[] $targets
-	 * @return bool
+	 * @param string|null $expiry Optional expiry in a format acceptable to wfTimestamp(),
+	 *   null will not create expiries, or leave them unchanged should they already exist.
+	 * @return bool Whether database transactions were performed.
 	 */
-	public function addWatchBatchForUser( UserIdentity $user, array $targets ) {
+	public function addWatchBatchForUser(
+		UserIdentity $user,
+		array $targets,
+		?string $expiry = null
+	) {
 		if ( $this->readOnlyMode->isReadOnly() ) {
 			return false;
 		}
@@ -757,7 +847,8 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 			$items[] = new WatchedItem(
 				$user,
 				$target,
-				null
+				null,
+				$expiry
 			);
 			$this->uncache( $user, $target );
 		}
@@ -772,6 +863,11 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 			// if there's already an entry for this page
 			$dbw->insert( 'watchlist', $toInsert, __METHOD__, [ 'IGNORE' ] );
 			$affectedRows += $dbw->affectedRows();
+
+			if ( $this->expiryEnabled ) {
+				$affectedRows += $this->updateOrDeleteExpiries( $dbw, $user->getId(), $toInsert, $expiry );
+			}
+
 			if ( $ticket ) {
 				$this->lbFactory->commitAndWaitForReplication( __METHOD__, $ticket );
 			}
@@ -786,6 +882,100 @@ class WatchedItemStore implements WatchedItemStoreInterface, StatsdAwareInterfac
 		return (bool)$affectedRows;
 	}
 
+	/**
+	 * Insert/update expiries, or delete them if the expiry is 'infinity'.
+	 *
+	 * @param IDatabase $dbw
+	 * @param int $userId
+	 * @param array $rows
+	 * @param string|null $expiry
+	 * @return int Number of affected rows.
+	 */
+	private function updateOrDeleteExpiries(
+		IDatabase $dbw,
+		int $userId,
+		array $rows,
+		?string $expiry = null
+	): int {
+		if ( null === $expiry ) {
+			// null expiry means do nothing, 0 rows affected.
+			return 0;
+		}
+
+		// Build the giant `(...) OR (...)` part to be used with WHERE.
+		$conds = [];
+		foreach ( $rows as $row ) {
+			$conds[] = $dbw->makeList(
+				[
+					'wl_user' => $userId,
+					'wl_namespace' => $row['wl_namespace'],
+					'wl_title' => $row['wl_title']
+				],
+				$dbw::LIST_AND
+			);
+		}
+		$cond = $dbw->makeList( $conds, $dbw::LIST_OR );
+
+		if ( wfIsInfinity( $expiry ) ) {
+			// Rows should be deleted rather than updated.
+			$dbw->deleteJoin(
+				'watchlist_expiry',
+				'watchlist',
+				'we_item',
+				'wl_id',
+				[ $cond ],
+				__METHOD__
+			);
+
+			return $dbw->affectedRows();
+		}
+
+		// TODO: Refactor with Special:Userrights::expiryToTimestamp() ?
+		//   Difference here is we need to accept null as being 'no changes'.
+		//   Validation of the expiry should probably happen before this method is called, too.
+		$unix = strtotime( $expiry );
+		if ( !$unix || $unix === -1 ) {
+			// Invalid expiry, 0 rows effected.
+			return 0;
+		}
+		$expiry = wfTimestamp( TS_MW, $expiry );
+
+		return $this->updateExpiries( $dbw, $expiry, $cond );
+	}
+
+	/**
+	 * Update the expiries for items found with the given $cond.
+	 * @param IDatabase $dbw
+	 * @param string $expiry
+	 * @param string $cond
+	 * @return int Number of affected rows.
+	 */
+	private function updateExpiries( IDatabase $dbw, string $expiry, string $cond ): int {
+		// First fetch the wl_ids from the watchlist table.
+		// We'd prefer to do a INSERT/SELECT in the same query with IDatabase::insertSelect(),
+		// but it doesn't allow us to use the "ON DUPLICATE KEY UPDATE" clause.
+		$wlIds = (array)$dbw->selectFieldValues( 'watchlist', 'wl_id', $cond, __METHOD__ );
+
+		$expiry = $dbw->timestamp( $expiry );
+
+		$weRows = array_map( function ( $wlId ) use ( $expiry, $dbw ) {
+			return [
+				'we_item' => $wlId,
+				'we_expiry' => $expiry
+			];
+		}, $wlIds );
+
+		// Insert into watchlist_expiry, updating the expiry for duplicate rows.
+		$dbw->upsert(
+			'watchlist_expiry',
+			$weRows,
+			'we_item',
+			[ 'we_expiry' => $expiry ]
+		);
+
+		return $dbw->affectedRows();
+	}
+
 	/**
 	 * @since 1.27
 	 * @param UserIdentity $user
diff --git a/includes/watcheditem/WatchedItemStoreInterface.php b/includes/watcheditem/WatchedItemStoreInterface.php
index 20244c39e75..551088c4884 100644
--- a/includes/watcheditem/WatchedItemStoreInterface.php
+++ b/includes/watcheditem/WatchedItemStoreInterface.php
@@ -177,22 +177,28 @@ interface WatchedItemStoreInterface {
 	/**
 	 * Must be called separately for Subject & Talk namespaces
 	 *
-	 * @since 1.31
+	 * @since 1.31 Method added.
+	 * @since 1.35 Accepts $expiry parameter.
 	 *
 	 * @param UserIdentity $user
 	 * @param LinkTarget $target
+	 * @param string|null $expiry Optional expiry timestamp in any format acceptable to wfTimestamp().
+	 *   null will not create an expiry, or leave it unchanged should one already exist.
 	 */
-	public function addWatch( UserIdentity $user, LinkTarget $target );
+	public function addWatch( UserIdentity $user, LinkTarget $target, ?string $expiry = null );
 
 	/**
-	 * @since 1.31
+	 * @since 1.31 Method added.
+	 * @since 1.35 Accepts $expiry parameter.
 	 *
 	 * @param UserIdentity $user
 	 * @param LinkTarget[] $targets
+	 * @param string|null $expiry Optional expiry timestamp in any format acceptable to wfTimestamp(),
+	 *   null will not create expiries, or leave them unchanged should they already exist.
 	 *
 	 * @return bool success
 	 */
-	public function addWatchBatchForUser( UserIdentity $user, array $targets );
+	public function addWatchBatchForUser( UserIdentity $user, array $targets, ?string $expiry = null );
 
 	/**
 	 * Removes an entry for the UserIdentity watching the LinkTarget
diff --git a/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php b/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
index 4bd54e6f60b..fb83629450a 100644
--- a/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
+++ b/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
@@ -16,6 +16,10 @@ class WatchedItemStoreIntegrationTest extends MediaWikiTestCase {
 		parent::setUp();
 		self::$users['WatchedItemStoreIntegrationTestUser']
 			= new TestUser( 'WatchedItemStoreIntegrationTestUser' );
+
+		$this->setMwGlobals( [
+			'wgWatchlistExpiry' => true,
+		] );
 	}
 
 	private function getUser() {
@@ -107,6 +111,76 @@ class WatchedItemStoreIntegrationTest extends MediaWikiTestCase {
 		);
 	}
 
+	public function testWatchAndUnWatchItemWithExpiry(): void {
+		$user = $this->getUser();
+		$title = Title::newFromText( 'WatchedItemStoreIntegrationTestPage' );
+		$store = MediaWikiServices::getInstance()->getWatchedItemStore();
+
+		$store->addWatch( $user, $title, '20300101000000' );
+		$this->assertSame(
+			'20300101000000',
+			$store->loadWatchedItem( $user, $title )->getExpiry()
+		);
+
+		// Invalid expiry, nothing should change.
+		$store->addWatch( $user, $title, 'invalid expiry' );
+		$this->assertSame(
+			'20300101000000',
+			$store->loadWatchedItem( $user, $title )->getExpiry()
+		);
+
+		// Changed to infinity, so expiry row should be removed.
+		$store->addWatch( $user, $title, 'infinity' );
+		$this->assertNull(
+			$store->loadWatchedItem( $user, $title )->getExpiry()
+		);
+
+		// Updating to a valid expiry.
+		$store->addWatch( $user, $title, '20500101000000' );
+		$this->assertSame(
+			'20500101000000',
+			$store->loadWatchedItem( $user, $title )->getExpiry()
+		);
+
+		// Expiry in the past, should not be considered watched.
+		$store->addWatch( $user, $title, '20090101000000' );
+
+		// Test isWatch(), which would normally pull from the cache. In this case
+		// the cache should bust and return false since the item has expired.
+		$this->assertFalse(
+			$store->isWatched( $user, $title )
+		);
+	}
+
+	public function testWatchAndUnwatchMultipleWithExpiry(): void {
+		$user = $this->getUser();
+		$title1 = Title::newFromText( 'WatchedItemStoreIntegrationTestPage1' );
+		$title2 = Title::newFromText( 'WatchedItemStoreIntegrationTestPage1' );
+		$store = MediaWikiServices::getInstance()->getWatchedItemStore();
+
+		$timestamp = '20500101000000';
+		$store->addWatchBatchForUser( $user, [ $title1, $title2 ], $timestamp );
+
+		$this->assertSame(
+			$timestamp,
+			$store->loadWatchedItem( $user, $title1 )->getExpiry()
+		);
+		$this->assertSame(
+			$timestamp,
+			$store->loadWatchedItem( $user, $title2 )->getExpiry()
+		);
+
+		// Clear expiries.
+		$store->addWatchBatchForUser( $user, [ $title1, $title2 ], 'infinity' );
+
+		$this->assertNull(
+			$store->loadWatchedItem( $user, $title1 )->getExpiry()
+		);
+		$this->assertNull(
+			$store->loadWatchedItem( $user, $title2 )->getExpiry()
+		);
+	}
+
 	public function testWatchBatchAndClearItems() {
 		$user = $this->getUser();
 		$title1 = Title::newFromText( 'WatchedItemStoreIntegrationTestPage1' );
diff --git a/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php b/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
index ef0c3a90a8a..7bfa775ee30 100644
--- a/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
+++ b/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
@@ -5,6 +5,7 @@ use MediaWiki\Revision\RevisionLookup;
 use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\User\UserIdentityValue;
 use PHPUnit\Framework\MockObject\MockObject;
+use Wikimedia\Rdbms\IDatabase;
 use Wikimedia\Rdbms\LBFactory;
 use Wikimedia\Rdbms\LoadBalancer;
 use Wikimedia\TestingAccessWrapper;
@@ -169,6 +170,8 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 	 *     * readOnlyMode
 	 *     * nsInfo
 	 *     * revisionLookup
+	 *     * expiryEnabled
+	 * @return WatchedItemStore
 	 */
 	private function newWatchedItemStore( array $mocks = [] ) : WatchedItemStore {
 		return new WatchedItemStore(
@@ -180,7 +183,8 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 			$mocks['readOnlyMode'] ?? $this->getMockReadOnlyMode(),
 			1000,
 			$mocks['nsInfo'] ?? $this->getMockNsInfo(),
-			$mocks['revisionLookup'] ?? $this->getMockRevisionLookup()
+			$mocks['revisionLookup'] ?? $this->getMockRevisionLookup(),
+			$mocks['expiryEnabled'] ?? true
 		);
 	}
 
@@ -1146,19 +1150,26 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testLoadWatchedItem_existingItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
-				$this->getFakeRow( [ 'wl_notificationtimestamp' => '20151212010101' ] )
+				$this->getFakeRow( [
+					'wl_notificationtimestamp' => '20151212010101',
+					'we_expiry' => '20300101000000'
+				] )
 			) );
 
 		$mockCache = $this->getMockCache();
@@ -1177,20 +1188,25 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$this->assertInstanceOf( WatchedItem::class, $watchedItem );
 		$this->assertEquals( 1, $watchedItem->getUser()->getId() );
 		$this->assertEquals( 'SomeDbKey', $watchedItem->getLinkTarget()->getDBkey() );
+		$this->assertSame( '20300101000000', $watchedItem->getExpiry() );
 		$this->assertSame( 0, $watchedItem->getLinkTarget()->getNamespace() );
 	}
 
 	public function testLoadWatchedItem_noItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue( [] ) );
@@ -1231,26 +1247,21 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 	public function testRemoveWatch_existingItem() {
 		$mockDb = $this->getMockDb();
 		$mockDb->expects( $this->once() )
+			->method( 'selectField' )
+			->willReturn( [ 1, 2 ] );
+		$mockDb->expects( $this->exactly( 2 ) )
 			->method( 'delete' )
 			->withConsecutive(
 				[
 					'watchlist',
-					[
-						'wl_user' => 1,
-						'wl_namespace' => 0,
-						'wl_title' => [ 'SomeDbKey' ],
-					],
+					[ 'wl_id' => [ 1, 2 ] ]
 				],
 				[
-					'watchlist',
-					[
-						'wl_user' => 1,
-						'wl_namespace' => 1,
-						'wl_title' => [ 'SomeDbKey' ],
-					]
+					'watchlist_expiry',
+					[ 'we_item' => [ 1, 2 ] ]
 				]
 			);
-		$mockDb->expects( $this->exactly( 1 ) )
+		$mockDb->expects( $this->exactly( 2 ) )
 			->method( 'affectedRows' )
 			->willReturn( 2 );
 
@@ -1276,29 +1287,12 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 	public function testRemoveWatch_noItem() {
 		$mockDb = $this->getMockDb();
 		$mockDb->expects( $this->once() )
-			->method( 'delete' )
-			->withConsecutive(
-				[
-					'watchlist',
-					[
-						'wl_user' => 1,
-						'wl_namespace' => 0,
-						'wl_title' => [ 'SomeDbKey' ],
-					]
-				],
-				[
-					'watchlist',
-					[
-						'wl_user' => 1,
-						'wl_namespace' => 1,
-						'wl_title' => [ 'SomeDbKey' ],
-					]
-				]
-			);
-
-		$mockDb->expects( $this->once() )
-			->method( 'affectedRows' )
-			->willReturn( 0 );
+			->method( 'selectField' )
+			->willReturn( null );
+		$mockDb->expects( $this->never() )
+			->method( 'delete' );
+		$mockDb->expects( $this->never() )
+			->method( 'affectedRows' );
 
 		$mockCache = $this->getMockCache();
 		$mockCache->expects( $this->never() )->method( 'get' );
@@ -1341,19 +1335,26 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testGetWatchedItem_existingItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
-				$this->getFakeRow( [ 'wl_notificationtimestamp' => '20151212010101' ] )
+				$this->getFakeRow( [
+					'wl_notificationtimestamp' => '20151212010101',
+					'we_expiry' => '20300101000000'
+				] )
 			) );
 
 		$mockCache = $this->getMockCache();
@@ -1379,6 +1380,7 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$this->assertInstanceOf( WatchedItem::class, $watchedItem );
 		$this->assertEquals( 1, $watchedItem->getUser()->getId() );
 		$this->assertEquals( 'SomeDbKey', $watchedItem->getLinkTarget()->getDBkey() );
+		$this->assertSame( '20300101000000', $watchedItem->getExpiry() );
 		$this->assertSame( 0, $watchedItem->getLinkTarget()->getNamespace() );
 	}
 
@@ -1414,15 +1416,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testGetWatchedItem_noItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue( [] ) );
@@ -1467,18 +1473,22 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testGetWatchedItemsForUser() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'select' )
 			->with(
-				'watchlist',
-				[ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp' ],
-				[ 'wl_user' => 1 ]
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp', 'we_expiry' ],
+				[ 'wl_user' => 1, 'we_expiry IS NULL OR we_expiry > 20200101000000' ]
 			)
 			->will( $this->returnValue( [
 				$this->getFakeRow( [
 					'wl_namespace' => 0,
 					'wl_title' => 'Foo1',
 					'wl_notificationtimestamp' => '20151212010101',
+					'we_expiry' => '20300101000000'
 				] ),
 				$this->getFakeRow( [
 					'wl_namespace' => 1,
@@ -1503,7 +1513,12 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 			$this->assertInstanceOf( WatchedItem::class, $watchedItem );
 		}
 		$this->assertEquals(
-			new WatchedItem( $user, new TitleValue( 0, 'Foo1' ), '20151212010101' ),
+			new WatchedItem(
+				$user,
+				new TitleValue( 0, 'Foo1' ),
+				'20151212010101',
+				'20300101000000'
+			),
 			$watchedItems[0]
 		);
 		$this->assertEquals(
@@ -1528,12 +1543,15 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$mockLoadBalancer = $this->getMockLBFactory( $mockDb, $dbType );
 		$user = new UserIdentityValue( 1, 'MockUser', 0 );
 
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'select' )
 			->with(
-				'watchlist',
-				[ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp' ],
-				[ 'wl_user' => 1 ],
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp', 'we_expiry' ],
+				[ 'wl_user' => 1, 'we_expiry IS NULL OR we_expiry > 20200101000000' ],
 				$this->isType( 'string' ),
 				[ 'ORDER BY' => [ 'wl_namespace ASC', 'wl_title ASC' ] ]
 			)
@@ -1561,15 +1579,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testIsWatchedItem_existingItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
@@ -1600,15 +1622,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testIsWatchedItem_noItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue( [] ) );
@@ -1903,15 +1929,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 
 	public function testResetNotificationTimestamp_noItem() {
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue( [] ) );
@@ -1936,15 +1966,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$title = new TitleValue( 0, 'SomeDbKey' );
 
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
@@ -2141,15 +2175,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$mockNextRevision = $this->createNoOpMock( RevisionRecord::class );
 
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
@@ -2226,15 +2264,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$title = new TitleValue( 0, 'SomeDbKey' );
 
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue( false ) );
@@ -2311,15 +2353,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$title = new TitleValue( 0, 'SomeDbKey' );
 
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
@@ -2400,15 +2446,19 @@ class WatchedItemStoreUnitTest extends MediaWikiTestCase {
 		$title = new TitleValue( 0, 'SomeDbKey' );
 
 		$mockDb = $this->getMockDb();
+		$mockDb->expects( $this->once() )
+			->method( 'addQuotes' )
+			->willReturn( '20200101000000' );
 		$mockDb->expects( $this->once() )
 			->method( 'selectRow' )
 			->with(
-				'watchlist',
-				'wl_notificationtimestamp',
+				[ 'watchlist', 'watchlist_expiry' ],
+				[ 'wl_notificationtimestamp', 'we_expiry' ],
 				[
 					'wl_user' => 1,
 					'wl_namespace' => 0,
 					'wl_title' => 'SomeDbKey',
+					'we_expiry IS NULL OR we_expiry > 20200101000000'
 				]
 			)
 			->will( $this->returnValue(
diff --git a/tests/phpunit/includes/watcheditem/WatchedItemUnitTest.php b/tests/phpunit/includes/watcheditem/WatchedItemUnitTest.php
new file mode 100644
index 00000000000..0c5f7d53382
--- /dev/null
+++ b/tests/phpunit/includes/watcheditem/WatchedItemUnitTest.php
@@ -0,0 +1,23 @@
+<?php
+
+use MediaWiki\User\UserIdentityValue;
+
+/**
+ * @covers WatchedItem
+ */
+class WatchedItemUnitTest extends MediaWikiTestCase {
+
+	public function testIsExpired() {
+		$user = new UserIdentityValue( 7, 'MockUser', 0 );
+		$target = new TitleValue( 0, 'SomeDbKey' );
+
+		$notExpired1 = new WatchedItem( $user, $target, null, '20500101000000' );
+		$this->assertFalse( $notExpired1->isExpired() );
+
+		$notExpired2 = new WatchedItem( $user, $target, null );
+		$this->assertFalse( $notExpired2->isExpired() );
+
+		$expired = new WatchedItem( $user, $target, null, '20010101000000' );
+		$this->assertTrue( $expired->isExpired() );
+	}
+}