Jay Dean Haas (born December 2, 1953) is an American professional golfer formerly of the PGA Tour who now plays on the Champions Tour.

Haas was born in St. Louis, Missouri, and grew up in Belleville, Illinois. He attended Wake Forest University and was a member of the NCAA Championship team of the middle 1970s with Curtis Strange and Bob Byman that Golf World has called "the greatest college team of all time". He won the individual championship in 1975. He turned professional in 1976.

Haas has had a solid career on the PGA Tour, winning nine times between 1978 and 1993. He had a resurgence in 2003, when he finished in the top 30 on the money list for the first time since 1995 and made the United States Presidents Cup team. The following year he was one of Hal Sutton's two captain's picks for the Ryder Cup, and made his third appearance in that event.

Haas was eligible to play in Champions Tour events from the start of the 2004 season and he lost to Hale Irwin by one stroke at the Senior PGA Championship in his first appearance at that level. He was still featured in the top 20 of the Official World Golf Ranking after his 50th birthday. In 2005, he won twice on the Champions Tour, while also continuing to play regularly on the PGA Tour. In April 2006, he won back to back events on the Champions Tour and the following month he won a playoff at the Oak Tree Golf Club with Brad Bryant at the Senior PGA Championship to claim his first senior major and he went on to top the 2006 Champions Tour money list. He was named the Champions Tour Player of the Year in 2006 as well. Haas won the 2008 Charles Schwab Cup to win two out of the last three cups.

After winning the Greater Hickory Classic at Rock Barn in September 2009, Haas won his third senior major and 14th Champions Tour event in October at the Constellation Energy Senior Players Championship. He came from 5 strokes behind with a final round 6-under-par 64 to win by 1 over 54-hole leader Tom Watson. In June 2012, Haas won his 16th title on the Champions Tour, cruising to a five stroke victory over Larry Mize and Kirk Triplett at the Principal Charity Classic.

Haas comes from a distinguished family of golfers. He is a nephew of 1968 Masters winner Bob Goalby, and has several other relations in golf including his second son Bill who has played on the PGA Tour since 2006. His oldest son Jay Jr., brother Jerry Haas, and brother-in-law Dillard Pruitt also played on the PGA Tour.

He was voted the 2006 Bob Jones Award, the highest honor given by the United States Golf Association in recognition of distinguished sportsmanship in golf. In February 2005, he received the Payne Stewart Award, and in April 2005, he received the Murray Award for his cooperation with the media. He has made the cut 592 times in the PGA Tour, more than any other player.

Haas currently resides in Greenville, South Carolina.