Circus produced four singles. "Womanizer" debuted at number 96 on the US Billboard Hot 100 and ascended to the summit in its second week, registering the largest leap on the chart at the time. It became Spears' best-selling single in the country since her debut "...Baby One More Time" (1998). "Circus" debuted and peaked at number three on the Billboard Hot 100; consequently, Circus became Spears' first album since her debut ...Baby One More Time (1999) to have two top-ten singles. Subsequent singles "If U Seek Amy" and "Radar" peaked at numbers 19 and 88 on the Billboard Hot 100, respectively. To further promote the album, Spears embarked on the world tour The Circus Starring Britney Spears (2009). 

Circus is the sixth studio album by American singer Britney Spears. It was released to coincide with her 27th birthday on December 2, 2008, in the United States, by Jive Records. Transitioning from the "darker and more urban" themes of her fifth studio album Blackout (2007), Spears wanted to make her next project "a little bit lighter". She recorded much of the album between March and September 2008, after being involuntarily placed under a conservatorship earlier that year, following her highly publicized personal struggles in 2007. As executive producers, Larry Rudolph and Teresa LaBarbera Whites enlisted Spears' previous collaborators such as Max Martin, Bloodshy & Avant, Guy Sigsworth and Danja, as well as new ones, including Dr. Luke, Benny Blanco and Claude Kelly. Their efforts resulted in a primarily pop and dance record, whose lyrical themes addressed fame, infidelity, and infatuation.