diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index e3d10601ca..95672f5350 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -3342,6 +3342,18 @@ function smilies_init() {
 		);
 	}
 
+	/**
+	 * Filter all the smilies.
+	 *
+	 * This filter must be added before `smilies_init` is run, as
+	 * it is normally only run once to setup the smilies regex.
+	 *
+	 * @since 4.6.0
+	 *
+	 * @param array $wpsmiliestrans List of the smilies.
+	 */
+	$wpsmiliestrans = apply_filters('smilies', $wpsmiliestrans);
+
 	if (count($wpsmiliestrans) == 0) {
 		return;
 	}
diff --git a/tests/phpunit/tests/formatting/Smilies.php b/tests/phpunit/tests/formatting/Smilies.php
index 9cd3b06f1c..7d7ae0cef5 100644
--- a/tests/phpunit/tests/formatting/Smilies.php
+++ b/tests/phpunit/tests/formatting/Smilies.php
@@ -312,4 +312,46 @@ class Tests_Formatting_Smilies extends WP_UnitTestCase {
 		// standard smilies, use_smilies: OFF
 		update_option( 'use_smilies', 0 );
 	}
+
+	/**
+	 * Test to ensure smilies can be removed with a filter
+	 *
+	 * @ticket 35905
+	 */
+	public function test_smilies_filter_removes_smilies() {
+		add_filter( 'smilies', array( $this, '_filter_remove_smilies' ) );
+		smilies_init();
+		remove_filter( 'smilies', array( $this, '_filter_remove_smilies' ) );
+
+		$txt = ':oops: I did it again';
+
+		$this->assertEquals( $txt, convert_smilies( $txt ) );
+	}
+
+	/**
+	 * Test to ensure smilies can be added with a filter
+	 *
+	 * @ticket 35905
+	 */
+	public function test_smilies_filter_adds_smilies() {
+		add_filter( 'smilies', array( $this, '_filter_add_smilies' ) );
+		smilies_init();
+		remove_filter( 'smilies', array( $this, '_filter_add_smilies' ) );
+
+		$txt = 'You played with my <3';
+		$expected_txt = 'You played with my \xe2\x9d\xa4';
+
+		$this->assertEquals( $expected_txt, convert_smilies( $txt ) );
+	}
+
+
+	 public function _filter_remove_smilies( $wpsmiliestrans ) {
+		unset( $wpsmiliestrans[':oops:'] );
+		return $wpsmiliestrans;
+	 }
+
+	 public function _filter_add_smilies( $wpsmiliestrans ) {
+		$wpsmiliestrans['<3'] = '\xe2\x9d\xa4';
+		return $wpsmiliestrans;
+	 }
 }