Fowler, who is ranked 59th in the Official World Golf Ranking, becomes the 12th player to commit to joining the league, which is scheduled to begin play in 2024.
TGL has now signed 12 of the 18 players who will compete on six three-man teams of PGA Tour players in match play on a virtual course that will include a short-game complex for chipping and putting.
The two-hour matches will be played in prime time on Monday nights. Last month, TGL broke ground on an arena on the campus of Palm Beach State College in Palm Beach Gardens, Florida. There will be 15 matches, plus semifinals and a final.
Fowler, 34, last won on tour at the 2019 WM Phoenix Open. He remains one of the most popular players in the sport and has enjoyed a resurgence this year after struggling much of the past two seasons. He has six top-10 finishes in 10 starts this season, including a tie for 13th at the Players last week. He also tied for sixth at the Fortinet Championship and tied for second at the Zozo Championship.
In 2014, Fowler finished in the top five in all four majors, including ties for second at the U.S. Open and The Open. He was solo second at the 2018 Masters.