diff --git src/wp-includes/formatting.php src/wp-includes/formatting.php
index a0438e9c53..93a3e9558d 100644
--- src/wp-includes/formatting.php
+++ src/wp-includes/formatting.php
@@ -1926,6 +1926,9 @@ function remove_accents( $string ) {
 			// grave accent
 			'Ǜ' => 'U',
 			'ǜ' => 'u',
+			// Greek and Coptic
+			'΅Ι' => 'I',
+			'ΐ' => 'i',
 		);
 
 		// Used for locale-specific rules
diff --git tests/phpunit/tests/formatting/RemoveAccents.php tests/phpunit/tests/formatting/RemoveAccents.php
index 32ea89e5f1..4046c3beed 100644
--- tests/phpunit/tests/formatting/RemoveAccents.php
+++ tests/phpunit/tests/formatting/RemoveAccents.php
@@ -143,4 +143,14 @@ class Tests_Formatting_RemoveAccents extends WP_UnitTestCase {
 
 		$this->assertEquals( 'Dd', remove_accents( 'Đđ' ) );
 	}
+
+	/**
+	 * @ticket 44793
+	 */
+	public function test_remove_greek_coptic() {
+		$input  = '΅Ιΐ';
+		$output = 'Ii';
+
+		$this->assertEquals( $output, remove_accents( $input ), 'remove_accents replaces greek coptic' );
+	}
 }