Justin Arch "Jay" Williamson IV (born February 7, 1967) is an American professional golfer who currently plays on the PGA Tour.
Williamson was born in St. Louis, Missouri. After graduating from Trinity College, he turned professional in 1990.
Williamson has no PGA Tour victories, although he has finished 2nd twice, including at the 2008 John Deere Classic, in which he lost to Kenny Perry in a one-hole playoff. He won once on the Nationwide Tour: the 2007 Fort Smith Classic. He has more than $5 million in career earnings.