A winger-turned-central midfielder, Giggs has retired from Wales duty but in February agreed a new deal with United, tying him to the club until the summer of 2013 and into his 23rd year at Old Trafford.
Wales' current best player is Gareth Bale but he ruled himself out of contention for the Olympics because of a back injury.
Great Britain has not fielded an Olympic team since the Rome Games 52 years ago because football federations in Scotland, Wales and Northern Ireland feared losing their independence within FIFA.
The world body assured the three federations that their status wouldn't be affected by participating in the 16-team competition at the London Games.
Britain play their opening match against Senegal at Old Trafford on July 26, faces the United Arab Emirates three days later at Wembley and Uruguay on Aug. 1 at the Millennium Stadium.
18-man squad:
Goalkeepers: Jack Butland (England; Birmingham City), Jason Steele (England; Middlesbrough)
Defenders: Ryan Bertrand (England; Chelsea), Steven Caulker (England; Swansea City), Craig Dawson (England; West Bromwich Albion), Micah Richards (England; Manchester City), Danny Rose (England; Tottenham Hotspur), Neil Taylor (Wales; Swansea City), James Tomkins (England; West Ham United)
Midfielders: Joe Allen (Wales; Swansea City), Tom Cleverley (England; Manchester United), Jack Cork (England; Southampton), Ryan Giggs (Wales; Manchester United), Aaron Ramsey (Wales; Arsenal), Scott Sinclair (England; Swansea City)
Forwards: Craig Bellamy (Wales; Liverpool), Marvin Sordell (England; Bolton Wanderers), Daniel Sturridge (England; Chelsea)
SNTV