The Loening XSL was an American submarine-based reconnaissance flying boat designed and built by Grover Loening Aircraft Company for the United States Navy.
First flown in 1931, the Loening XSL was a lightweight flying-boat designed to be folded up and stored in an 8-foot-diameter watertight tube on the deck of a submarine. It was a single-seat, mid-wing monoplane powered by a 1100NaN0 Warner Scarab radial engine mounted above the wing driving a pusher propeller. Originally designated the XSL-1 by the Navy, it was re-designated XSL-2 in 1932 when it was re-engined with a 1600NaN0 Menasco B-6 engine. Only the prototype was built; it was not ordered into production.