Supermarine Sea Otter

Sea Otter
One of the two constructed prototypes, photographed in 1942
Role Air-Sea rescue
National origin United Kingdom
Manufacturer Supermarine
First flight 23 September 1938
Introduction November 1944
Status Out of production, out of service
Primary users Royal Air Force
Royal Navy
Royal Danish Air Force
Royal Australian Navy
Produced 1942–1945
Number built 292
Developed from Supermarine Walrus

The Supermarine Sea Otter was an amphibious aircraft designed and built by the British aircraft manufacturer Supermarine. It was the final biplane flying boat to be designed by the company, and the last biplane to enter service with both the Royal Navy and the Royal Air Force (RAF).

The Sea Otter was developed as a refinement of the Supermarine Walrus. It was designed to be used for longer range operations, to perform dive bombing and to operate from a wider range of vessels than its predecessor. It was first known as the Stingray. The aircraft's development was protracted by Supermarine's commitments to the Walrus and the Spitfire programmes.

The Sea Otter first flew on 23 September 1938. A production order was issued in 1942. Upon its introduction during the latter years of the Second World War, the Sea Otter was primarily tasked with maritime patrol and air-sea rescue duties by both the RAF and the Royal Navy. After the war, the type was procured by the Royal Danish Air Force, Dutch Naval Aviation Service, and the Royal Australian Navy. Supermarine undertook the conversion of surplus Sea Otters to be used by civil operators.