The 115-cap No.10 gets the nod over Jonathan Sexton after impressing in the Emerald Isle's last pool match, a resounding 36-6 victory over Italy, which confirmed their progression to the knock-out rounds.
Rory Best is Kidney's only doubt and will to undergo a late fitness test on a shoulder injury sustained against Italy, with back-up hooker Sean Cronin on stand-by, while Mike Sherry has flown out as cover.
Kidney talked up the challenge Wales will pose but insists O'Gara, who played second fiddle to Sexton during the RBS 6 Nations, will not be targeted as a weak-spot for Warren Gatland's side to exploit.
"They have quite an array of places where they can attack - I don't think they'll pick anyone in particular," said Kidney.
"Wales are a better side now because before you knew where they would attack, but now they attack other places too. It's going to be a case of everyone defending their own zone.
"Playing Wales is a huge challenge. They got the better of us in March and are going well.
"They only lost to the kick of a ball against South Africa, otherwise they'd be on four wins from four games.
"They beat England and Argentina during the warm up games as well. They have a few younger players who have brought their own spark. The senior guys are showing good form too.
"They're showing different trends in the way they play, but are more unpredictable than before. If it was possible to read them before, it's more difficult now."
15. Rob Kearney -Leinster
14. Tommy Bowe - Ospreys
13. Brian O'Driscoll - Leinster
12. Gordon D'Arcy - Leinster
11. Keith Earls - Ulster
10. Ronan O'Gara - Munster
9. Conor Murray - Munster
1. Cian Healy - Leinster
2. Rory Best - Ulster, or Sean Cronin - Leinster
3. Mike Ross - Leinster
4. Donncha O'Callaghan - Munster
5. Paul O'Connell - Munster
6. Stephen Ferris - Ulster
7. Sean O'Brien - Leinster
8. Jamie Heaslip - Leinster
16. Sean Cronin -Leinster, or Damien Varley - Munster
17. Tom Court- Ulster
18. Donnacha Ryan - Munster
19. Denis Leamy - Munster
20. Eoin Reddan - Leinster
21. Jonathan Sexton - Leinster
22. Andrew Trimble - Ulster