The 29-year-old held a four-shot advantage heading into the final round in Northern Ireland, but he showed nerves of steel with a closing 68 to seal his first Open Championship.
He carded six birdies and a double bogey to finish with a 17-under-par total, and briefly led by eight shots at one point, as the chasing pack failed to challenge against the newly-crowned Champion Golfer of the Year.
Americans dominated the top of the leaderboard as Harris English proved to be Scheffler’s closest rival at 13 under, with Chris Gotterup backing up last week’s Genesis Scottish Open win in solo third.
Scheffler’s triumph – his second major win of the year and fourth overall – means he has now secured three of the four major titles, with only the US Open eluding him from completing the career Grand Slam.
“It’s a very special feeling. It takes a lot of work to get to this point in my career,” Scheffler said.
“This was a tough week. It was challenging. The golf course was playing really tough and I had to focus very hard over the course of the weekend.
“Being able to walk up 18 with the tournament in hand is a really tough thing to describe. It’s a really cool feeling. I have a lot of gratitude towards being able to accomplish something like this.
“It’s a high level of focus over 72 holes of a tournament. This was, I felt like, one of my best performances mentally.”
The challengers were hoping to make inroads on Scheffler’s advantage, but the American swiftly shut the door with a brilliant approach inside two feet at the first to climb up to 15 under.
Haotong Li followed suit by birdieing the opening hole, only to bogey the second to slip back to ten under.
Another stunning approach into the fourth resulted in another birdie for Scheffler and when Li bogeyed the same hole, the World Number One was seven clear.
A third gain of the day at the fifth saw Scheffler briefly stretch his lead to eight at 17 under, but his Chinese playing partner returned to ten under with a birdie at the same hole.
Scheffler showed his quality with a pair of superb par saves from the sixth to remain seven ahead just as Gotterup birdied the ninth to reach 11 under.
The leader’s advantage was trimmed to four when he inexplicably double-bogeyed the eighth after needing two attempts out of the fairway bunker.
However, Scheffler bounced back with a birdie at the ninth and when Li and Gotterup bogeyed the tenth and 11th respectively, the American was six clear at 16 under.
Gotterup birdied the 12th and 13th to climb to 12 under, however, Scheffler led by five shots with five to play after rolling in a birdie at the 12th.
English, who came in with birdie-birdie-par finish, was in the clubhouse at 13 under as Scheffler’s advantage was cut to four with only two holes remaining.
Despite parring his way home, Scheffler became only the second player since James Braid in 1908 to win each of their first four Major Championships by three of more shots.
English carded an eagle, four birdies and a dropped shot in his 66 for solo second, while Gotterup continued his meteoric rise with a closing 67 to finish in third at 12 under.
Wyndham Clark, who won the 2023 U.S. Open, climbed up to fourth after a final-round 65 and was joined by Englishman Matt Fitzpatrick and Li at 11 under.
Home favourite Rory McIlroy sat alongside Ryder Cup team-mate Robert MacIntyre and defending champion Xander Schauffele one shot further back in a share of seventh.
