In the backs Leigh Halfpenny, Alex Cuthbert, George North, Jonathan Davies and Sexton all make their Lions Test debuts, while experience is provided by Brian O'Driscoll and Mike Philips, who have nine Lions Tests between them.
The pack contains a wealth of Lions Test experience with Jamie Heaslip, Tom Croft, Paul O'Connell, Alun Wyn Jones and Adam Jones sharing 17 Tests.
English loosehead prop Alex Corbisiero, who joined the tour as a replacement, also makes his debut along with tour captain Sam Warburton and hooker Tom Youngs.
British & Irish Lions tour manager Andy Irvine said: "We are now at the business end of the tour. You can feel the excitement and commitment within the squad now that we are back in Brisbane and the first Test is just days away.
"I congratulate all the players who are making their Lions Test debuts on Saturday. Playing against the Wallabies for the Lions is a major milestone in a player's career and I am confident they will all uphold the history and tradition of the Lions by giving their all."
Head coach Warren Gatland explained: "After six matches we have arrived at the first Test and have selected our strongest possible side with only Jamie Roberts, Tommy Bowe and Manu Tuilagi unavailable for selection.
"The Wallabies at home pose a huge challenge but the Test team contains 20 of the players that played against the Waratahs in what was our best match to date. We now have a couple of more days of match preparation to ensure we improve again on that performance."
BRITISH & IRISH LIONS Team & Replacements (v Australia, 2013 British & Irish Lions Tour First Test, Suncorp Stadium, Brisbane, Saturday, June 22, kick-off 8.05pm local time/11.05am Irish time):
15. Leigh Halfpenny (Cardiff Blues/Wales)
14. Alex Cuthbert (Cardiff Blues/Wales)
13. Brian O'Driscoll (Leinster/Ireland)
12. Jonathan Davies (Scarlets/Wales)
10. Jonathan Sexton (Leinster/Ireland)
9. Mike Phillips (Bayonne/Wales)
1. Alex Corbisiero (London Irish/England)
2. Tom Youngs (Leicester Tigers/England)
3. Adam Jones (Ospreys/Wales)
4. Alun Wyn Jones (Ospreys/Wales)
5. Paul O'Connell (Munster/Ireland)
6. Tom Croft (Leicester Tigers/England)
7. Sam Warburton (Cardiff Blues/Wales) (capt)
8. Jamie Heaslip (Leinster/Ireland)
16. Richard Hibbard (Ospreys/Wales)
17. Mako Vunipola (Saracens/England)
18. Dan Cole (Leicester Tigers/England)
19. Geoff Parling (Leicester Tigers/England)
20. Dan Lydiate (Newport Gwent Dragons/Wales)
21. Ben Youngs (Leicester Tigers/England)
22. Owen Farrell (Saracens/England)
23. Sean Maitland (Glasgow Warriors/Scotland)