BrainTeaser was a British game show, first broadcast in 2002, produced by Endemol UK subsidiary Cheetah Productions.

BrainTeaser was live, with phone-in viewer puzzles being announced and played during the show in addition to the studio game. During its run until 7 March 2007, it aired on Channel 5 Mondays to Fridays, usually for an hour around lunchtime, with Alex Lovell as the main presenter. Until the end of 2005, Lovell rotated presenting duties on a weekly basis with Craig Stevens, Rachel Pierman and Jonny Gould, at different times in the show's history.

The programme was suspended on 8 March 2007 after it was revealed that the production company had misled viewers regarding winners of the viewer puzzles. Actions included publishing fictional names and presenting a member of the production team as a 'winner'. On 26 June 2007, Five announced that the show had been axed after 7 March 2007 due to the Phone-In Scandal.