The 2011 Open Championship was a men's major golf championship and the 140th Open Championship, held from 14 to 17 July at Royal St George's Golf Club in Sandwich, Kent, England. Darren Clarke won his first and to date only major championship, three strokes ahead of runners-up Dustin Johnson and Phil Mickelson.

This was the fourteenth Open Championship at Royal St George's; the last was in 2003 when Ben Curtis won his only major championship and finished as the only player under par at −1, a stroke clear of Vijay Singh and Thomas Bjørn.

The course was lengthened by 105 yards (96 m) and par returned to 70, having been 71 in 2003 when the fourth hole was a par five.

^ Hole No. 4 was a par 5 in 2003

Lengths of the course for previous Opens (since 1950):

Each year, around two-thirds of The Open Championship field consists of players that are fully exempt from qualifying for the Open. The players who have already qualified for the 2011 Open Championship are listed below. Each player is classified according to the first category in which he qualified, but other categories are shown in parentheses.

1. Past Open Champions aged 60 or under on 17 July 2011
Mark Calcavecchia, Stewart Cink (2,4,20), Ben Curtis (2,4), John Daly, David Duval (2), Ernie Els (2,4,6,7,16), Todd Hamilton (2), Pádraig Harrington (2,4,6,7,14,20), Paul Lawrie, Tom Lehman, Justin Leonard (4), Sandy Lyle, Mark O'Meara, Louis Oosthuizen (2,4,5,6,7)

2. The Open Champions for 2001–2010