The 1931 Open Championship was the 66th Open Championship, held 3–5 June at Carnoustie Golf Links in Carnoustie, Angus, Scotland. Scottish-born Tommy Armour outlasted José Jurado of Argentina by a single stroke to win his only Open title, and his third and final major championship.
Qualifying took place on 1–2 June. Entries played 18 holes at Carnoustie and 18 holes at Panmure Golf Club. The leading 100 players and ties qualified. The qualifying score was 160 and 109 players qualified. Macdonald Smith led the qualifiers on 141. The top 60 and ties would make the cut and qualify for the final 36 holes. Prize money for the Championship was increased to £500 with £100 for the champion, £75 for second place, £50 for third, £30 for fourth, £25 for fifth, £20 for sixth and seventh, £15 for eighth and ninth and £10 for the next 15 players.
Johnny Farrell, Henry Cotton, and Bill Twine each had a share of the lead after the first round after shooting even-par 72. Cotton shared the lead with Jurado after the second round, with Armour a stroke behind. Cotton slipped back with a 79 in the third round, while Jurado shot 73 to open up a three shot lead over Macdonald Smith and Arthur Havers, with Farrell and Reg Whitcombe four back and Armour, Percy Alliss, and Gene Sarazen five back. Despite a shaky finish which saw him need 11 strokes on the last two holes, Alliss took the clubhouse lead of 298 after a 73. Armour surpassed that total after a course-record 71, finishing at 296 total. Still on the course when Armour finished, Jurado needed a 75 to win the title. After making the turn in 36, he found trouble on the back-nine. Jurado arrived at the 17th needing to finish with fives on the last two holes to tie Armour, but his drive found the burn and he carded a 6. Now needing a 4 on the last, he hit his approach to 9 feet (2.7 m), but his putt to tie just missed, securing the championship for Armour.
Armour, age 36 and a U.S. citizen, played the Open Championship just once more. He returned to Britain to defend his title in 1932 and finished in 17th place.
Defending champion Bobby Jones retired from competition in 1930 and did not compete.