"Just When I Needed You Most" is a 1979 hit single by American singer- songwriter Randy VanWarmer. It was inspired by two personal events: the breakup with a girlfriend and the breakdown of his old car. Written six months after his breakup, the song became a hit after its release in February 1979. It reached No. 1 on the Billboard Adult Contemporary chart, No. 4 on the Billboard Hot 100, and No. 8 on the UK Singles Chart. VanWarmer's high-pitched vocals and a notable autoharp instrumental break contributed to the song's appeal. The song expresses deep heartbreak and the feeling of abandonment at a time of greatest need, resonating with a wide audience and earning gold record status.

The lyrics convey the emotional situation of the narrator who is left alone "just when I needed you most," highlighting themes of loss, vulnerability, and longing.