What's Missing is a song written by Jimmy Jam and Terry Lewis and recorded by American recording artist Alexander O'Neal.

It is the fourth single from the singer's self-titled debut studio album, Alexander O'Neal (1985).

Following the moderately successful chart performances of the Alexander O'Neal singles "Innocent", "If You Were Here Tonight", and "A Broken Heart Can Mend", "What's Missing" was released as the album's fourth single.

Alexander O'Neal's 5th hit single and it reached #90 in the UK Singles Chart.

In the United States, the single reached #8 on Billboard's Hot R&B/Hip-Hop Singles & Tracks.