Big Brother 2005, also known as Big Brother 6, was the sixth series of the British reality television series Big Brother, in which a number of contestants live in an isolated house trying to avoid being evicted by the public with the aim of winning a large cash prize at the end of the run.
The series launched on Channel 4 on 27 May 2005 and ended on 12 August 2005, lasting eleven weeks, at the time the longest the programme had lasted (subsequent series extended the duration to thirteen weeks), Davina McCall returned as host for her sixth consecutive year. Thirteen housemates entered on launch night with an additional three being introduced in Week 4, this was the first series where late entry housemates survived public votes and made it to the final. Anthony Hutton was chosen as the winner on Day 78, receiving £50,000, Eugene Sully who finished second received the other half of the prize money due to a task on Day 76.
Makosi and Craig returned in 2009 to compete in a task for a few hours, in 2010 Makosi was a contestant in Ultimate Big Brother. She entered on Day 1 and became the second Ultimate housemate to be evicted on Day 11. Anthony also returned as a guest to have a picnic date with Makosi. The Big Brother eye for this series was also used for the Serbian Big Brother series, Veliki brat.
The first reports of this series were announced in March 2005 when Channel 4 confirmed that Big Brother would return for its sixth series in the summer of that year. Within that announcement the company revealed that host Davina McCall, Big Brother's Little Brother presenter Dermot O'Leary, and Big Brother's Big Mouth (called Big Brother's EForum the previous year) host Russell Brand would return along with the show. Soon after, Channel 4 programming director Kevin Lygo told the press that Big Brother 5's evil theme would not return despite its success the previous year and that the programme would be renewed for 2006 and beyond.
In April, Channel 4 confirmed that Big Brother 6 would start on 27 May 2005, in keeping with the tradition that Big Brother UK would start in late May. On 30 April 2005, Channel 4 revealed the eye for the series, a sliced mirror of alternating black and blue strips, in reality two eyes on top of each other. This helped fuel rumours about two houses, an idea that although never coming to fruition, was put into practice during the 2003 series of Big Brother in Australia. On 9 May 2005, Channel 4 began airing countdown bumpers, starting at eighteen days rather than the usual ten days before the launch; subsequent series began airing countdown bumpers ten days before the premiere. Channel 4 contradicted itself two days before the launch show, confirming that Big Brother 6 would, in fact, be evil. The broadcaster also told the press that there would be thirteen housemates with a theme of "unlucky thirteen," inspired by triskaidekaphobia.