He was also named the Golf Coaches Association of America (GCAA) Division I Jack Nicklaus National Player of the Year.

[10] On August 6, Cantlay lost to Ethan Tracy in the Western Amateur final at the North Shore Country Club in Glenview, Illinois.

[citation needed] In June 2012, Cantlay decided to forgo his final two years of college to turn professional.

[13] Cantlay was the number one amateur in the world before turning pro, holding the top spot for a record 55 weeks.

[14][15] In his second start of the 2017 season, Cantlay regained his PGA Tour card with a runner-up finish at the Valspar Championship.

In his second start of the 2018 season, on November 5, 2017, Cantlay won his first PGA Tour title at the Shriners Hospitals for Children Open on the second extra hole of a three-man playoff.

[17] Cantlay shot a final round of 64 to come from four strokes behind the 54-hole leader Martin Kaymer and win his second PGA Tour title.

In December, Cantlay played on the U.S. team at the 2019 Presidents Cup at Royal Melbourne Golf Club in Australia.

[19] At The American Express in January 2021, Cantlay made the halfway cut on the number; and then fired twenty birdies over the weekend, including in a 11-under-par final round 61 to post a 22-under total and the clubhouse lead.

[21] On August 29, 2021, Cantlay won the BMW Championship on the sixth hole of a sudden-death playoff over Bryson DeChambeau.

[22] The following week, Cantlay, on September 5, 2021, won the Tour Championship at East Lake Golf Club in Atlanta, Georgia.

[26] Early in the 2023 season, Cantlay contended in back-to-back weeks at the Masters Tournament and the RBC Heritage, finishing T14 and third, respectively.

[27][28][29][30][31] In September 2023, Cantlay played on the U.S. team in the 2023 Ryder Cup at Marco Simone Golf and Country Club in Guidonia, Rome, Italy.

The European team won 16.5–11.5 and Cantlay went 2–2–0 including a win in his Sunday singles match against Justin Rose.

Cantlay allegedly refused to wear a team hat at the event due to a dispute about whether the players should be paid for playing.

The controversy led to European fans openly mocking Cantlay and chanting and singing "Hats off to your bank account".