diff --git a/src/wp-includes/option.php b/src/wp-includes/option.php
index 1ea13263a5..5b450515a4 100644
--- a/src/wp-includes/option.php
+++ b/src/wp-includes/option.php
@@ -186,25 +186,45 @@ function form_option( $option ) {
 function wp_load_alloptions() {
 	global $wpdb;
 
-	if ( ! wp_installing() || ! is_multisite() )
+	if ( ! wp_installing() || ! is_multisite() ) {
 		$alloptions = wp_cache_get( 'alloptions', 'options' );
-	else
+	} else {
 		$alloptions = false;
+	}
 
-	if ( !$alloptions ) {
+	if ( ! $alloptions ) {
 		$suppress = $wpdb->suppress_errors();
-		if ( !$alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'" ) )
+		if ( ! $alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'" ) ) {
 			$alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options" );
-		$wpdb->suppress_errors($suppress);
+		}
+		$wpdb->suppress_errors( $suppress );
+
 		$alloptions = array();
 		foreach ( (array) $alloptions_db as $o ) {
 			$alloptions[$o->option_name] = $o->option_value;
 		}
-		if ( ! wp_installing() || ! is_multisite() )
+
+		if ( ! wp_installing() || ! is_multisite() ) {
+			/**
+			 * Filters all options before caching them.
+			 *
+			 * @since 4.9.0
+			 *
+			 * @param array $alloptions Array with all options.
+			 */
+			$alloptions = apply_filters( 'pre_cache_alloptions', $alloptions );
 			wp_cache_add( 'alloptions', $alloptions, 'options' );
+		}
 	}
 
-	return $alloptions;
+	/**
+	 * Filters all options after retrieving them.
+	 *
+	 * @since 4.9.0
+	 *
+	 * @param array $alloptions Array with all options.
+	 */
+	return apply_filters( 'alloptions', $alloptions );
 }
 
 /**
diff --git a/tests/phpunit/tests/option/wpLoadAllOptions.php b/tests/phpunit/tests/option/wpLoadAllOptions.php
new file mode 100644
index 0000000000..12696abe7a
--- /dev/null
+++ b/tests/phpunit/tests/option/wpLoadAllOptions.php
@@ -0,0 +1,109 @@
+<?php
+/**
+ * Test wp_load_alloptions().
+ *
+ * @group option
+ */
+class Tests_Option_WP_Load_Alloptions extends WP_UnitTestCase {
+	protected $alloptions = null;
+
+	function tearDown() {
+		$this->alloptions = null;
+		parent::tearDown();
+	}
+
+	function test_if_alloptions_is_cached() {
+		$this->assertNotEmpty( wp_cache_get( 'alloptions', 'options' ) );
+	}
+
+	/**
+	 * @depends test_if_alloptions_is_cached
+	 */
+	function test_if_cached_alloptions_is_deleted() {
+		$this->assertTrue( wp_cache_delete( 'alloptions', 'options' ) );
+	}
+
+	/**
+	 * @depends test_if_alloptions_is_cached
+	 */
+	function test_if_alloptions_are_retrieved_from_cache() {
+		global $wpdb;
+		$before = $wpdb->num_queries;
+		wp_load_alloptions();
+		$after = $wpdb->num_queries;
+
+		// Database has not been hit.
+		$this->assertEquals( $before, $after );
+	}
+
+	/**
+	 * @depends test_if_cached_alloptions_is_deleted
+	 */
+	function test_if_alloptions_are_retrieved_from_database() {
+		global $wpdb;
+
+		// Delete the existing cache first.
+		wp_cache_delete( 'alloptions', 'options' );
+
+		$before = $wpdb->num_queries;
+		wp_load_alloptions();
+		$after = $wpdb->num_queries;
+
+		// Database has been hit.
+		$this->assertEquals( $before + 1, $after );
+	}
+
+	/**
+	 * @depends test_if_cached_alloptions_is_deleted
+	 */
+	function test_filter_pre_cache_alloptions_is_called() {
+		$temp = wp_installing();
+
+		/**
+		 * Set wp_installing() to false.
+		 *
+		 * If wp_installing is false and the cache is empty, the filter is called regardless if it's multisite or not.
+		 */
+		wp_installing( false );
+
+		// Delete the existing cache first.
+		wp_cache_delete( 'alloptions', 'options' );
+
+		add_filter( 'pre_cache_alloptions', array( $this, 'return_pre_cache_filter' ) );
+		$all_options = wp_load_alloptions();
+
+		// Value could leak to other tests if not reset.
+		wp_installing( $temp  );
+
+		// Filter was called.
+		$this->assertEquals( $this->alloptions, $all_options );
+	}
+
+	/**
+	 * @depends test_if_alloptions_is_cached
+	 */
+	function test_filter_pre_cache_alloptions_is_not_called() {
+		$temp = wp_installing();
+
+		/**
+		 * Set wp_installing() to true.
+		 *
+		 * If wp_installing is true and it's multisite, the cache and filter are not used.
+		 * If wp_installing is true and it's not multisite, the cache is used (if not empty), and the filter not.
+		 */
+		wp_installing( true );
+
+		add_filter( 'pre_cache_alloptions', array( $this, 'return_pre_cache_filter' ) );
+		wp_load_alloptions();
+
+		// Value could leak to other tests if not reset.
+		wp_installing( $temp );
+
+		// Filter was not called.
+		$this->assertNull( $this->alloptions );
+	}
+
+	function return_pre_cache_filter( $alloptions ) {
+		return $this->alloptions = $alloptions;
+	}
+}