The Antonov An-4 was a Soviet seaplane developed in the early 1950s as a float-equipped version of the proven Antonov An-2. The goal was to create a versatile aircraft capable of operating in regions lacking runways. Instead of conventional landing gear, the An-4 featured large floats, enabling takeoffs and landings on lakes, rivers, and coastal waters.

Like the An-2, the An-4 was powered by a powerful radial engine and was distinguished by its robust construction and ability to fly reliably even under challenging conditions. It could be used for transporting passengers and cargo, as well as for supply flights, medical missions, and other civil operations.

Despite its excellent qualities, the Antonov An-4 remained a niche variant. It was produced in relatively small numbers, as the demand for seaplanes was lower than for the standard wheeled version. Today, the An-4 represents a rare and interesting chapter in the history of Antonov aviation, demonstrating the versatility of the successful An-2 design.