SIKORSKY, Igor Ivanovich (1889–1972), Russian-born American aeronautical engineer and manufacturer.

Sikorsky was born in Kiev, Ukraine, and educated at the naval college in Saint Petersburg, and in Kiev and Paris. At first he experimented in helicopter design. In 1913 he designed, built, and flew the first successful multiengined airplane. Later he built military aircraft for Russia and France.

Sikorsky moved (1919) to the U.S. and later helped organize an aircraft company that produced a series of multiengined flying boats for commercial service. Sikorsky became an American citizen in 1928. In the late 1930s Sikorsky returned to developing helicopters and produced the first successful helicopter in the western hemisphere. Sikorsky-designed helicopters were used exclusively by the U.S. Army Air Forces during World War II.