"Ch-Check It Out" is a song by alternative hip-hop group Beastie Boys, released as the first single off their sixth studio album, To the 5 Boroughs (2004), on May 3, 2004. The song heavily samples "(Sittin' On) The Dock of the Bay" by Peggy Lee. Following its appearance on an episode of American teen drama television series The O.C. in April 2004, the song was released as a single on May 3, 2004.