Free Jazz: A Collective Improvisation is a studio album by American jazz saxophonist Ornette Coleman, released in September 1961.
The album features what Coleman called a "double quartet," i.e., two self-contained jazz quartets: each with a reed instrument, trumpet, bass, and drums.

The two quartets are heard in separate channels, with Coleman's working quartet at the time in the left channel, and the second quartet, including
the former Coleman rhythm section of Charlie Haden and Ed Blackwell, on the right.

The two quartets play simultaneously. Free Jazz was the first album-length improvisation at thirty-seven minutes, unheard of at the time.

The original LP package incorporated Jackson Pollock's 1954 painting The White Light. The cover is a gatefold with a cutout window in the lower right corner allowing a glimpse of the painting;

opening the cover revealed the full artwork, along with liner notes by critic Martin Williams.
Free Jazz served as the blueprint for later large-ensemble free jazz recordings such as Ascension by John Coltrane and Machine Gun by Peter Brötzmann.

Free Jazz is available as a limited edition of 1000 individually numbered copies on white vinyl.