Fowler is one of four golfers in the "Golf Boys" group along with fellow PGA Tour players Ben Crane, Bubba Watson and Hunter Mahan. The Golf Boys released a YouTube video of the song "Oh Oh Oh" on the eve of the 2011 U.S. Open. Farmers Insurance is donating $1,000 for every 100,000 views of the video. The charitable proceeds will support both Farmers and Ben Crane charitable initiatives.
In the 2012–13 season, Lowry regained his first team place, playing in the left-back and central defense positions until he missed one game after picking up a yellow card for the fifth time against Bristol City on 2 October 2012. After making his first team return as a left-back, Lowry then provided assist for the winning goal when he set up a goal for Chris Woods, in a 1–0 win against his former club, Leeds United on 18 November 2012. Lowry was then banned for two matches between 19 January 2013 and 25 January 2013 after picking up a yellow card for the tenth time this season. Lowry then He "curled a superb, dipping free-kick" to score from 35 yards (32 m) as Millwall beat Charlton Athletic 2–0 at The Valley on 16 March 2013. Lowry played in all matches in the run up to the Lions' FA Cup semi final against Wigan Athletic at Wembley, though he missed one match in the 4th round against his former club, Aston Villa. In late-April, Lowry was given a three match ban after being booked for the fifteenth time this season. Despite this, Lowry finished the 2012–13 season, making forty-five appearance and scoring once in all competitions.
THE PLAYERS Championship: A week after collecting his first PGA TOUR victory, nearly became the first player since David Duval (1997) to post first two TOUR victories in back-to-back weeks, finishing T2 at THE PLAYERS, two strokes behind winner Matt Kuchar. Holed a birdie attempt from 21 feet, 7 inches on the par 3 17th in the final round to move to 11-under but couldn't convert a 7-foot, 7-inch birdie on No. 18 that would have given him the clubhouse lead at 12-under. Recorded his fifth career runner-up finish on TOUR in his 73rd start. His T2 performance came in his third start at THE PLAYERS and first in which he made the 36-hole cut. Moved into contention with a 66 in the third round, a career low at TPC Sawgrass. Entered the final round three shots off the 54-hole pace.
In June 2015, he became the first SMU Mustang to win the NCAA individual championship, recording a score of 280 (−8) to win by one stroke. In August, he won the U.S. Amateur title, defeating Derek Bard 7 & 6 in the 36-hole final. He became the fifth player to win both the NCAA and U.S. Amateur titles in the same year, joining Jack Nicklaus (1961), Phil Mickelson (1990), Tiger Woods (1996), and Ryan Moore (2004).
PGA Championship: Finished T3 and two strokes behind McIlroy at the PGA Championship in his 20th major championship start, with T19 in 2013 the previous-best finish in four prior PGA Championship starts. Became the first to claim top-five finishes in all four majors since Woods in 2005. Since 1934, is just the third player to perform the feat, joining Woods in 2000 and 2005 and Jack Nicklaus in 1971 and 1973. Played all four majors in 32-under, with McIlroy second on the list, at 27-under.
Shell Houston Open: After opening with an 8-under 64 for a one-stroke lead on day one, added rounds of 71-67-70 to finish T3 at the Shell Houston Open. Erased a seven-shot deficit in the third round and started the final round three shots behind 54-hole leader Sung Kang, but a final-round 70 saw him finish four strokes behind winner Russell Henley. With 27 birdies on the week (tied for most with Henley), marked his most birdies in a single event.
Hyundai Tournament of Champions: Finished T6 in a Monday-start-Tuesday-finish event, the season-opening, 54-hole Hyundai Tournament of Champions. The event "started" twice during the regularly scheduled first round Friday and later Sunday, but both times PGA TOUR rules staff halted play due to unplayable windy conditions and subsequently voided all scores that had taken place. As the first player off the tee, he ended up hitting three "opening" shots of the season.
Deutsche Bank Championship: Shot a final-round 3-under 68 to come from one shot back and defeat third-round leader Henrik Stenson at the Deutsche Bank Championship, good for his third career PGA TOUR victory. Earned the win at age 26 years, 8 months, 25 days in his 150th career start. Collected 2,000 points and moved from No. 22 to No. 3 in the FedExCup standings. Has come from behind to win all three of his PGA TOUR events, with his first two wins via playoffs (2012 Wells Fargo Championship and 2015 PLAYERS Championship). Became the sixth consecutive come-from-behind winner at TPC Boston.
On June 3, 2018, DeChambeau won the Memorial Tournament in Dublin, Ohio, in a sudden-death playoff against Kyle Stanley and An Byeong-hun, after the three finished regulation play tied at −15. After Stanley bogeyed the first hole of sudden death, DeChambeau then proceeded to win with a birdie on the second hole, giving him his second win on the tour.
OHL Classic at Mayakoba: Birdied two of his last three holes at the OHL Classic at Mayakoba to fire a final-round 67 and finish in 2nd place, one shot back of Patton Kizzire. In his first start at the event, opened with a bogey-free, 6-under 65 to sit three back of Kizzire's lead. Followed with three-consecutives rounds of 67 in rounds two through four, resulting in a score of 18-under 266. Due to inclement weather Saturday, played his final two rounds on Sunday.
Though he appeared in two matches as an un-used substitute for Aston Villa in the 2010–11 season, Lowry continued to be remain out of the first team and in January 2011, Lowry signed for Championship side Sheffield United until the end of the season making his first start for the Blades away at Coventry City a day later. Lowry made eighteen appearances for the Blades but with the club in decline he was unable to prevent them from being relegated at the end of the season.
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.