ORP Jastrząb ("Hawk") was a former S-class submarine, originally of the United States Navy, in Polish service between 1941 and 1942, when she was lost to friendly fire.

The United States' S-class submarines, often simply called S-boats, were the first class of submarines with a significant number built to United States Navy designs. They made up the bulk of the USN submarine service in the interwar years and could be found in every theater of operations. While not considered fleet submarines, they were the first submarines in the USN designed for open ocean, blue water operations. All previous submarines had been intended for harbor or coastal defense. These boats were intended to have greater speed and range than previous classes, with improved habitability and greater armament.