Stormy Six were an Italian progressive and folk rock band founded in Milan in 1966. They performed and recorded until 1983, mostly as a sextet but occasionally as a quartet, a quintet and a septet. Although their line-up changed considerably over the years, founding member Franco Fabbri remained with the group for its entire duration. In May 1993 they performed at a re-union concert in Milan, which was recorded and released on a CD, Un Concerto (1995).

Stormy Six were best known as one of the five original Rock in Opposition (RIO) bands that performed at the first RIO festival in March 1978 in London. They later participated actively in the shaping of RIO as an organisation and performed across Europe with other RIO and related bands.