diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index be27b07ca6..90a5de4bda 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -4202,7 +4202,7 @@ function esc_url( $url, $protocols = null, $_context = 'display' ) {
 		return $url;
 	}
 
-	$url = str_replace( ' ', '%20', $url );
+	$url = str_replace( ' ', '%20', ltrim( $url ) );
 	$url = preg_replace( '|[^a-z0-9-~+_.?#=!&;,/:%@$\|*\'()\[\]\\x80-\\xff]|i', '', $url );
 
 	if ( '' === $url ) {
diff --git a/tests/phpunit/tests/formatting/EscUrl.php b/tests/phpunit/tests/formatting/EscUrl.php
index 96698c19e8..9532976ce2 100644
--- a/tests/phpunit/tests/formatting/EscUrl.php
+++ b/tests/phpunit/tests/formatting/EscUrl.php
@@ -13,6 +13,7 @@ class Tests_Formatting_EscUrl extends WP_UnitTestCase {
 		$this->assertEquals( 'http://example.com/Mr%20WordPress', esc_url( 'http://example.com/Mr%20WordPress' ) );
 		$this->assertEquals( 'http://example.com/Mr%20%20WordPress', esc_url( 'http://example.com/Mr%20%20WordPress' ) );
 		$this->assertEquals( 'http://example.com/Mr+WordPress', esc_url( 'http://example.com/Mr+WordPress' ) );
+		$this->assertEquals( 'http://example.com/Mr+WordPress', esc_url( ' http://example.com/Mr+WordPress' ) );
 
 		$this->assertEquals( 'http://example.com/?foo=one%20two%20three&bar=four', esc_url( 'http://example.com/?foo=one two three&bar=four' ) );
 		$this->assertEquals( 'http://example.com/?foo=one%20two%20three&bar=four', esc_url( 'http://example.com/?foo=one%20two%20three&bar=four' ) );