"Luck" is a song written by Zachary Barnett, David Rublin, Matthew Sanchez and James Shelley of American pop rock band American Authors, co-written with producers Aaron Accetta and Shep Goodman. The song was originally recorded for their debut extended play, American Authors, and appears as the third track on the EP. The track later appeared as the fourth track on their debut studio album Oh, What a Life. The song was released by Island Records in Canada as a one-track single on March 3, 2014, becoming the fourth single by the band and the second release promoting Oh, What a Life, after "Trouble".