The 1911 Open Championship was the 51st Open Championship, held 26–30 June at Royal St George's Golf Club in Sandwich, England. Harry Vardon won the Championship for the fifth time after a playoff against Arnaud Massy.
There was no qualifying event and with 226 entries it was not possible for all the players to play 18 holes on the same day. The players were therefore divided into three "sections". Sections A and B played on the first day, while section C played on the second morning. Section A played their second rounds on the second afternoon, while sections B and C played their second rounds on the third day.
By the start of the contest the number of contestants had been reduced to 222, with 4 withdrawals. On the first day the Irish professional Michael Moran had the best round with a 72. On the second morning the players in Section C discovered that a number of the holes had been moved since the first day. Later in the day a letter of protest was drawn up by a group of professionals and presented to the authorities: "To the Committee of the Championship, 1911 - Gentlemen, we the undersigned competitors at this Championship meeting respectfully protest against the alteration of the course during the qualifying (sic) rounds." Play was somewhat easier on the second morning and the amateur Edward Blackwell led after a round of 71 with Moran joined on 72 by J.H. Taylor.
Of those in Section A, Ted Ray led after the second day with a score of 148. The Committee replied to the professionals "The Green Committee consider that in deciding to cut fresh holes each day they had adopted the best course possible under the terms of the competition, which were exceptional owing to the large entry, and though they regret that there was any dissatisfaction amongst the players, they decided that the protest could not be upheld." New holes were again cut on the third morning, so that Sections B and C played their second round to different holes to Section A. George Duncan led after two rounds with a score of 144, four ahead of Ray, Taylor and Vardon on 148. The leading 60 players and ties played 36 holes on the fourth day. The cut was at 162; 73 players made the cut with 15 players on 162.
Duncan had a poor third round of 83 which left Vardon with a three shot lead over Sandy Herd, Taylor and Massy.
Vardon was among the early starters in the afternoon and scored 80 for a total of 303. Harold Hilton, an amateur, reached the turn in 33 but took 43 for the last nine and finished a shot behind. Massy needed a 4 at the difficult final hole to tie. He reached the green with two woods and two putted to force a 36-hole playoff with Vardon.
Massy led the playoff after 10 holes but a 6 at the 14th and a disastrous 7 at the 17 meant that Vardon led by 5 after the first round. The lead extended to 7 after 27 holes and 10 after 34 holes. After Vardon reached the green in two at the 35th and Massy was in thick rough after two shots, Massy picked up his ball and conceded.