"Lock U Down" is a song by American recording artist Mýa Harrison on her fourth studio album Liberation (2007). It was written by Harrison along with Jason Boyd, Dwayne Carter, and Scott Storch, with production handled by the latter, and featured Young Money rapper Lil Wayne. The song was released as the album's official leading single after "Ayo!" failed to find success on the charts or at radio and eventually deemed as a promotional single only. The lyrics of the R&B-collaboration speak of a woman locking her man down when she has found the right one.