"Killer" is a song by Adamski and Seal. Written by Adam Tinley (Adamski) and Seal and produced by Adamski, "Killer" was Adamski's breakthrough single, but is now more notable for introducing Seal as a vocalist.

In 1991 Seal re-recorded "Killer" for his eponymous debut album, produced by Trevor Horn. The single release of Seal's version peaked at #8 in the UK, squeezed onto the Billboard Hot 100 at #100 and peaked at #9 on the Billboard Hot Dance Club Play chart with a remix by William Orbit. The music video for this version used computer-generated science-fiction themed imagery, largely built around a partial re-creation of the M. C. Escher print Another World.

The video was produced and directed by Don Searll. The song won Best British Video at the 1992 Brit Awards.

4 January 2005 saw a new single release of "Killer", containing new remixes of both "Killer" and "Crazy". This brought the single back to the Hot Dance Club Play chart, where it reached number one.