The Supermarine Seagull was a British amphibious, military flying boat and the last to be built by the Supermarine company. Design started during the Second World War but it did not fly until three years after the war had ended and the project was cancelled without it being adopted for service.

An amphibious aircraft or amphibian is an aircraft that can take off and land on both solid ground and water. They are typically fixed-wing, though amphibious helicopters do exist as well. Fixed-wing amphibious aircraft are seaplanes which are equipped with retractable wheels, at the expense of extra weight and complexity, plus diminished range and fuel economy compared to planes designed specifically for land-only or water-only operation. Some amphibians are fitted with reinforced keels which act as skis, allowing them to land on snow or ice with their wheels up.