In September, he signed a clothing deal with Puma. In the same month, he was also chosen as a captain's pick for the U.S. Ryder Cup team. At age 21 years and 9 months when the matches began, Fowler became the youngest U.S. Ryder Cup player of all time, and only European Sergio García was younger when he made his Ryder Cup debut in 1999. Fowler forfeited a hole during foursomes competition on the first match day because of a rules violation, by taking a permissible free drop from muddy conditions in an improper location, a mistake U.S. captain Corey Pavin attributed to Fowler's inexperience. On the final day of the competition in his singles match against Edoardo Molinari, Fowler birdied the last 4 holes to halve the match after having been 4 down after 12 holes.
In 2008, Fowler repeated as Sunnehanna Amateur champion. In the first round of the U.S. Open, Fowler shot a −1 (70) and was in a tie for 7th place. He was one of three amateurs to make the cut, along with Derek Fathauer and Michael Thompson. He ended the tournament tied for 60th. In October 2008 Fowler played on the Eisenhower Trophy team that finished second. He was the leading individual player.
On June 16, Fowler carded a round of 65 at Erin Hills to take the first round lead at the 2017 U.S. Open. Fowler equaled the lowest first round score at the U.S. Open and led by one stroke from Paul Casey and Xander Schauffele. He followed this up with a one over par 73 in the second round to fall out of the lead by one stroke, held by four other players. He shot 68-72 over the weekend to finish in a tie for fifth place. This gave Fowler his sixth top-5 finish in a major, but he is still yet to win. Fowler started the PGA Championship with a 2-under 69 which was two strokes behind the leaders. After rounds of 70-73, he closed out the year's last major with a 4-under 67, including a run of four consecutive birdies on holes 12 through 15. Despite his solid finish, Fowler ended up tied for fifth and was 3 strokes behind the winner, and friend, Justin Thomas. It was his seventh top-5 major finish, meaning he's had multiple top-5 finishes at every major.
On July 16, 2017, DeChambeau earned his first PGA Tour victory by winning the John Deere Classic by a single stroke over Patrick Rodgers. He carded a round of 65 in the final round to win his maiden title in his 40th start on tour. The win coming the week before, gained DeChambeau a place in the 2017 Open Championship, where he missed the cut after rounds of 76–77 (+13).