Wales star Sam Warburton was named as captain of the 2013 British and Irish squad for the tour of Australia but there was no place for England great Jonny Wilkinson.
At 24, Warburton becomes the youngest tour captain in Lions history, but there was no room in the 37-man touring party for either England captain Chris Robshaw or 2003 World Cup-winning star Wilkinson.
However, Ireland great and 2005 Lions captain Brian O'Driscoll was included, with the centre chosen for his fourth successive tour with the combined side.
The Lions will be looking for their first series win since 1997 when they defeated South Africa.
They face the Wallabies in the first of three Tests on June 22, after starting their tour against the Barbarians in Hong Kong on June 1.
Gatland, seconded from Wales to coach the Lions, selected 15 Welshmen with the Six Nations Grand Slam champions providing the bulk of his squad.
Full-backs: Leigh Halfpenny (WAL), Stuart Hogg (SCO), Rob Kearney (IRL);
Wings: Tommy Bowe (IRL), Alex Cuthbert (WAL), Sean Maitland (SCO), George North (WAL);
Centres: Jonathan Davies (WAL), Brian O'Driscoll (IRL), Jamie Roberts (Wales), Manu Tuilagi (England)
Fly-halves Owen Farrell (ENG), Jonathan Sexton (IRL)
Scrum-halves: Conor Murray (IRL), Mike Phillips (WAL), Ben Youngs (ENG)
Sam Warburton (WAL, capt), Justin Tipuric (WAL), Sean O'Brien (IRL), Dan Lydiate (WAL), Jamie Heaslip (IRL), Toby Faletau (WAL), Tom Croft (ENG)
Locks: Geoff Parling (ENG), Paul O'Connell (IRL), Alun-Wyn Jones (WAL), Richie Gray (SCO), Ian Evans (WAL)
Props: Dan Cole (ENG), Cian Healy (IRL), Gethin Jenkins (WAL), Adam Jones (WAL), Mako Vunipola (ENG), Matt Stevens (ENG)
Hookers: Tom Youngs (ENG), Richard Hibbard (WAL), Dylan Hartley (ENG)
Fixtures (all times GMT)
Jun 01: v Barbarians, Hong Kong (1130)
Jun 05: v Western Force, Perth (1000)
Jun 08: v Queensland Reds, Brisbane, (0930)
Jun 11: v Combined New South Wales-Queensland Country, Newcastle (0930)
Jun 15: v NSW Waratahs, Sydney (0930)
Jun 22: v AUSTRALIA, 1ST TEST, BRISBANE (1000)
Jun 25: v Melbourne Rebels, Melbourne (0930)
Jun 29: v AUSTRALIA, 2ND TEST, Melbourne (1000)
Jul 06: v AUSTRALIA, 3RD TEST, Sydney (1000)