Blake's 7 is a British science fiction television programme produced by the BBC. Four series of thirteen 50-minute episodes were broadcast on BBC1 between 1978 and 1981. It was created by Terry Nation, who also wrote the first series, produced by David Maloney (series 1–3) and Vere Lorrimer (series 4), and the script editor throughout its run was Chris Boucher, who wrote nine of its episodes. The main character for the first two series was Roj Blake, played by Gareth Thomas.

Blake's 7 was broadcast in 25 other countries. It had a low budget but featured many tropes of space opera, such as spaceships, robots, galactic empires and aliens. Critical responses have been varied; some reviewers praised the programme for its dystopian themes, strong characterisation, ambiguous morality and pessimistic tone, as well as displaying an "enormous sense of fun", but others have criticised its production values and dialogue, and accused it of lacking originality. It retains a sizeable and enthusiastic fan base, and was described in The Guardian's 40-year retrospective as "a bold show that wasn't afraid to break formulas".

A limited range of Blake's 7 merchandise was issued, and books, magazines and annuals published. The BBC released music and sound effects from the series, and several companies made Blake's 7 toys and models. Four video compilations were released between 1985 and 1990, and the entire programme was released in videocassette format beginning in 1991 and re-released during 1997, and as four DVD boxed sets between 2003 and 2006. The BBC produced two audio dramas during 1998 and 1999, featuring original cast members, that were broadcast by BBC Radio 4. Although proposals for live-action and animated remakes have not been realised, Blake's 7 has been revived with two series of audio dramas, a comedic short film, and a series of fan-made audio plays involving the original cast.