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 in support of her sixth studio album, Circus (2008). 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.

El circo protagonizado por Britney Spears, comúnmente conocido como The Circus Tour, fue la séptima gira de conciertos del cantante estadounidense Britney Spears. Fue lanzado en apoyo de su sexto álbum de estudio, Circus (2008). Los rumores de una gira surgieron ya en octubre de 2007, después de que Spears lanzó su quinto álbum de estudio Blackout; Sin embargo, se canceló debido a razones desconocidas.