O'Connor converted three of Australia's four tries against Italy last Sunday while scoring one himself, after coming on as a replacement in the 48th minute.
With the 21-year-old back in the side, there is a positional switch for fellow winger Adam Ashley-Cooper, who moves from the right to the left hand side of the backs division.
Drew Mitchell, the second top try scorer at the 2007 Rugby World Cup, has also been added to the replacements bench. He sat out the Tri Nations after sustaining an ankle injury during the Super 15 campaign.
Head coach Robbie Deans commented: "Drew has worked hard within the group, he has the background with us and is ready for this opportunity.
"While it is disappointing for Digby that he is going to be on the sidelines for a while, we are confident he will be available to us again before too long. His timelines will depend on how his rehabilitation goes, but the operation on Tuesday night went well."
Deans' first match in charge, back in June 2008, was against Ireland and resulted in an 18-12 win. Ashley-Cooper, Rocky Elsom, captain James Horwill and Stephen Moore are the only members of this weekend's team who started that night in Melbourne.
Notably, Queensland's Anthony Fainga'a will become the seventh different centre to line up opposite Brian O'Driscoll in the 11 Tests that the Ireland captain has played against Australia since 1999.
Giving his opinion of the current Ireland side, Deans added: "You only have to go back to this year's Six Nations when Ireland knocked England off to deny them a Grand Slam.
"They are a solid unit, filled with experienced performers. Their set piece is excellent, they have a big pack and they will be up for it, seeing this match as a great opportunity to make a statement.
"Crucially they have also troubled us in the past, and will believe they can do so again. We've never had it easy playing against them. Saturday night will be no difficult. It is going to take a big effort to get the job done."
AUSTRALIA Team & Replacements (v Ireland, 2011 Rugby World Cup Pool C, Eden Park, Saturday, September 17, kick-off 8.30pm local time/9.30am Irish time):
15 - Kurtley Beale (NSW Waratahs)
14 - James O'Connor (Western Force)
13 - Anthony Fainga'a (Queensland Reds)
12 - Pat McCabe (Brumbies)
11 - Adam Ashley-Cooper (Brumbies)
10 - Quade Cooper (Queensland Reds)
9 - Will Genia (Queensland Reds)
1 - Sekope Kepu (NSW Waratahs)
2 - Stephen Moore (Brumbies)
3 - Ben Alexander (Brumbies)
4 - Dan Vickerman (NSW Waratahs)
5 - James Horwill (Queensland Reds) (capt)
6 - Rocky Elsom (Brumbies)
7 - David Pocock (Western Force)
8 - Radike Samo (Queensland Reds)
16 - Tatafu Polota Nau (NSW Waratahs)
17 - James Slipper (Queensland Reds)
18 - Rob Simmons (Queensland Reds)
19 - Ben McCalman (Western Force)
20 - Scott Higginbotham (Queensland Reds)
21 - Luke Burgess (NSW Waratahs)
22 - Drew Mitchell (NSW Waratahs)
Follow the Ireland team in New Zealand on www.twitter.com/irfurugby.