The Circus Starring Britney Spears

The Circus Starring Britney Spears (commonly referred to as the Circus Tour) was the seventh concert tour by American singer Britney Spears. It was launched to promote her sixth studio album Circus. Rumors of a tour arose as early as October 2007, after Spears released her fifth studio album Blackout; however, it was cancelled due to unknown reasons. The tour was officially announced in December 2008, with dates for American and British venues revealed. The stage was composed of three rings and set in-the-round to resemble an actual circus. Fashion designers Dean and Dan Caten created the costumes. A giant cylinder screen was set above the stage to showcase videos and backdrops. Effects were provided by Solotech. Magician Ed Alonzo joined Spears during the second act. The setlist was composed generally from her albums In the Zone, Blackout and Circus. Spears announced she would tour Australia for the first time in June 2009.

The tour was described as a "pop extravaganza". It was divided into five segments. The Circus featured a metamorphosis of Spears from as a ringmaster to a slave, while being surrounded by different performers. House of Fun (Anything Goes) displayed a series of upbeat numbers with different themes, including magic and military. It ended with a Bollywood-inspired performance and a ballad in which Spears performed while floating on a giant umbrella. Freakshow/Peepshow featured a video interlude set to heavy metal music, and continued with dark and sexual performances. Electro Circ displayed energetic dance routines, and the encore consisted of a video montage of Spears's music videos and a police-themed performance. Some changes were made to the show throughout the tour. Several songs were remixed; Spears also performed "Mannequin" in selected European shows and covers of Duffy and Alanis Morissette in some North American dates.

The Circus Starring Britney Spears generated positive to mixed reception from critics. While some praised its aesthetics and deemed it as an entertaining show, others criticized Spears' lack of involvement during some segments. The tour was a commercial success, with a total gross of $131.8 million. A great number of tickets were sold within a week of the tour's announcement, which prompted supporters to add more dates. The tour also broke attendance records in many cities and all the North American shows were sold out. It became the fifth highest grossing tour of 2009, and the sixth highest grossing tour ever by a female artist. The show generated controversy on the Australian leg after a reporter said that a great number of fans had walked out during the performances.