Gary George Hallberg (born May 31, 1958) is an American professional golfer who has played on the PGA Tour, Nationwide Tour, and Champions Tour.

Hallberg was born in Berwyn, Illinois. He attended Wake Forest University in Winston-Salem, North Carolina and was a member of the golf team. He was a member of the 1977 Walker Cup team, and was the individual medalist at the 1979 NCAA Division I Men's Golf Championships. Hallberg had a couple of golf's historical firsts: he was the first four-time, first-team All-American in the history of intercollegiate golf, and he was the first player to obtain his PGA Tour card by winning a set level of money (in this case $8,000 in 1980) rather than by going to Qualifying School. He turned professional in 1980.

Hallberg won three PGA Tour events during his career. He was PGA Tour Rookie of the Year in 1980. His best finish in major championships was a T-6 at both the 1984 PGA Championship and The Masters in 1985. At the 1991 Open Championship, Hallberg was tied for the lead after 36 holes before finishing T32. During his late forties, he played mostly on the Nationwide Tour, winning once.

Hallberg began playing on the Champions Tour in 2008 after turning 50. He won his first event in 2010 at the Ensure Classic at Rock Barn. He shot a final round of 11-under par 61 in the final round to come from behind and win by one over Fred Couples and by two over Bernhard Langer. The win made him the fourth player to win on all the PGA Tour sponsored tours (PGA Tour, Nationwide Tour, and Champions Tour).

Hallberg has also done some analyst work for CNBC and NBC Sports. He lives in Castle Rock, Colorado. Gary's son Eric is also a professional golfer who qualified for the 2015 Frys.com Open.