Celebrity Big Brother 11 was the eleventh series of the British reality television series Celebrity Big Brother. It launched on 3 January 2013, and aired on Channel 5 and 5* for 23 days concluding on 25 January 2013. The series is part of a new two-year contract signed by Channel 5 with Endemol to air the show until 2014.
The series was won by Rylan Clark, with Heidi Montag and Spencer Pratt as runners-up. It was the fourth celebrity series to air on Channel 5 and the sixth series of Big Brother to air on the broadcaster since they acquired the show. With an average of 2.8 million, this was the highest rated series of the show (alongside Celebrity Big Brother 8) since its move to Channel 5, until it was surpassed by Celebrity Big Brother 13 in January 2014. It was also the last series of Big Brother to be presented by Brian Dowling, who was replaced by Emma Willis from the fourteenth regular series onwards.
In 2017, Heidi & Spencer returned to the house for Celebrity Big Brother 19 as All-Stars, representing this series. They were the eighth housemates to be evicted.
The official new eye logo for Celebrity Big Brother 11 was introduced on 30 November 2012. The new logo design follows the same pattern as for Big Brother 13 and Celebrity Big Brother 10, but with a new winter theme.
The official pictures of the Celebrity Big Brother 11 House, which features a winter theme, were released on 27 December 2012. The House features the same layout as the previous layout, with minor changes. The garden, again, has a pool and a hot tub.