Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials) for telecommunications and broadcasting, including television. They are among the tallest man-made structures.Similar structures include electricity pylons and towers for wind turbines.

Masts are usually named after the broadcasting organizations that use them, or after a nearby city or town.

Until August 8, 1991, the Warsaw radio mast was the world's tallest supported structure on land; its collapse left the KVLY/KTHI-TV mast as the tallest. There are over 50 radio structures in the United States that are 600 m (1968.5 ft) or taller.

In the case of a mast radiator or radiating tower, the whole mast or tower is itself the transmitting antenna.