"Countdown" is a song by American R&B singer Beyoncé Knowles from her fourth studio album, 4 (2011). It was written by Terius Nash, Shea Taylor, Knowles, Ester Dean, Cainon Lamb, Julie Frost, Michael Bivins, Nathan Morris and Wanya Morris. The song's development was motivated when Knowles wanted to create something different by mixing musical styles of the 1990s with the 1970s. "Countdown" was released on October 4, 2011 as the fourth single from the album.
Critics classified "Countdown" as a multi-genre song and praised the sampling of the countdown from "Uhh Ahh" by Boyz II Men. They compared it to singles from Dangerously in Love (2003) and B'Day (2006), noticing elements of funk music, and dancehall influences in the tradition of "Get Me Bodied" (2007). "Countdown" features a marching rhythm and contains an Afrobeat heavy brass riff. In the song, Knowles delivers a message of loyalty to her love interest and boasts of the ways they are lucky to have each other. Critics stated that "Countdown" may be the highlight of Knowles' career and the most experimental song that she has ever recorded. Following the leak of 4 in early June 2011, "Countdown" received minor rotation on radio that attributed to its debut at number 75 on the US Hot R&B/Hip-Hop Songs chart, where it peaked at number 12. It also charted at number 71 on the US Billboard Hot 100 chart and number one on the US Hot Dance Club Songs chart. "Countdown" peaked at number 35 on the UK Singles Chart and number nine on the UK R&B Chart.
Adria Petty directed the accompanying music video, which shows Knowles at different stages of her pregnancy and shows her as she makes references to art, fashion, and dance styles of the past. Reviewers wrote positively when they found that Knowles could dance even though she was pregnant. They also commended how Knowles channeled the classier highlights of pop, fashion, and film's past. However, the video faced controversy after viewers found that Knowles' choreography resembles the work of Belgian choreographer Anne Teresa De Keersmaeker. The song was part of Knowles' set lists during the revues 4 Intimate Nights with Beyoncé and Revel Presents: Beyoncé Live.