The Open Championship: Enjoyed his best finish among seven major championship starts, with a T5 at The Open Championship at Royal St. George's. Opened with three par-or-better rounds to enter the final round three strokes behind Darren Clarke. Closed with a 2-over 72 in windy conditions to finish tied with fellow Americans Chad Campbell and Anthony Kim.
“I was literally thinking I’d need surgery but I talked to Greg, he was like no, no, no, don’t do any of that, we’re going to teach your body to tolerate the force. Usually when ligaments get torn or bones get broken or whatever it’s because the muscles aren’t functioning properly, so thats what I’ve been doing.” He’s been focusing on exercises that get him into “extreme positions of rotations and flexions” at which point he adds weight to build mental and physical tolerance in those positions.
U.S. Open: Established the first-round lead at the U.S. Open with a 7-under 65 and was in the mix all week at Erin Hills. Followed with 73 to be one back through 36 holes. Third-round 68 had him two adrift headed into final round. Closed with even-par 72 to finish six back of Brooks Koepka at T5. In nine U.S. Open appearances, has advanced to the weekend five times and never broken par in the final round.
The Open Championship: Playing in the final group Sunday for the second straight time in a major championship, made a solid bid for the title, at The Open Championship, with a final-round, 5-under 67. Along with Garcia, finished second to Rory McIlroy by two strokes. With his finish at Royal Liverpool GC, became the only player of the season to claim top-five finishes in the year's first three major championships. He also became the first player to claim top-10 finishes in a season's first three majors since Woods achieved the feat in 2005. His T2 at Royal Liverpool supplanted his previous-best Open Championship finish (in four starts) of T5 in 2011. Rounds of 69-69-68-67 made him the only player in the field to post all four rounds in the 60s.
Lowry made his debut for the Glory on 30 January 2016, starting against Melbourne Victory. Lowry then scored his first Perth Glory goal on 20 February 2016 when he scored a header in the 41st minutes, to give Brisbane Roar a thrashing with a 6–3 win for Perth Glory. Throughout the 2015–16 season, Lowry established himself in the starting eleven and formed a central defense partnership with Alex Grant, as he made ten appearance for Perth Glory in his first half of the season.
U.S. Open: Playing alongside eventual-champion Martin Kaymer in the final pairing Sunday, followed up his career-best round (3-under 67) in a U.S. Open with a final-round, 2-over 72 to remain T2 (the sixth runner-up finish of his career). It was his best performance in six U.S. Open starts (previous-best finish was a T10 in 2013). It was also his top major championship showing among his 18 starts (previous-best finishes were T5s at the 2011 Open Championship and the 2014 Masters). His pairing with the 29-year-old Kaymer was just the third final grouping at the U.S. Open since 1965 with two players in their 20s. The others were John Mahaffey (28) and Jerry Pate (22) in 1976 and Woods (26) and Sergio Garcia (22) in 2002.
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).