The Douglas Dolphin is an American amphibious flying boat. While only 58 were built, they served a wide variety of roles including private air yacht, airliner, military transport, and search and rescue.

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.