Justin Arch "Jay" Williamson IV (born February 7, 1967) is an American professional golfer who has played on the PGA Tour and the Nationwide Tour.

He attended Trinity College and was a member of the Division III baseball and hockey teams.

Williamson has no PGA Tour victories, although he has finished second twice, both playoff losses – to Hunter Mahan at the 2007 Travelers Championship, and to Kenny Perry at the 2008 John Deere Classic.

He won once on the Nationwide Tour: the 2007 Fort Smith Classic.

[1] Nationwide Tour playoff record (0–1) PGA Tour playoff record (0–2) CUT = missed the halfway cut DQ = Disqualified T = Tied Note: Williamson never played in the Masters Tournament or the PGA Championship.