Smith said: "I haven't captained a team since my school days so I'm very excited about the achievement of leading the A-team. The strength in the team shows the growing depth in Australian rugby and it's a big opportunity for everyone to push for selection to the Test team.
"The Ospreys have lost quite a few players to the Wales squad but they have still got a very strong pack and have the experience of Justin Marshall and Jason Spice at scrum half. They are both fierce competitors."
Mark Gerrard starts at outside-half while Matt Rogers and Clyde Rathbone are both included among the replacements.
The Ospreys have lost a dozen players to the Wales squad that faces Australia on Saturday though can still draw upon the experience of eight internationals including Wales centre Sonny Parker and British Lions hooker Barry Williams as well as Marshall.
Australia: C Shepherd, S Staniforth, A Ashley-Cooper, G Fairbanks, M Turinui, M Gerrard, B Sheehan, N Henderson, T Polota-Nau, G Shepherdson, A Campbell, J Horwill, H McMenniman, D Lyons, G Smith (capt)
Replacements: S Moore, B Robinson, M Chisholm, S Hoiles, J Valentine, M Rogers, C Rathbone