Big Brother 4 (UK)

Big Brother 2003, also known as Big Brother 4, was the fourth series of the British reality television series Big Brother UK. The show followed twelve, known as housemates, who were isolated from the outside world for an extended period of time in a custom built House. Each week, one or more of the housemates were evicted by a public vote.

As with the previous three series, Big Brother 4 lasted 64 days. It launched on Channel 4 on 23 May 2003 and ended on 25 July 2003. Davina McCall returned as presenter for her fourth consecutive year. Twelve housemates entered on launch night, with one additional housemate being introduced in the sixth week.

The winner of this series was Guy Unger.

This series was preceded by series three and followed by series five.