The match is the third and final Autumn Test at the national stadium to be played in front of a capacity, 67,144 crowd, with Townsend's men keen to end the series in credit after an opening win over Samoa (44-38) and a narrow loss to World Champions New Zealand (22-17).
Townsend, said: "This is the third and final game of our autumn series and the players are looking forward to ending it on a high.
"Last weekend's game was a proper Test match - intense, competitive and full of drama. Unfortunately, we just fell short of our goal, and were disappointed with the loss, but take confidence going into the game against Australia."
He starts in place of wing Lee Jones - who misses out on the match-day 23 - to combine with Stuart Hogg and Tommy Seymour in the back-three, leaving an unchanged half-back pairing (Ali Price and Finn Russell) and midfield (Alex Dunbar and Huw Jones), providing Dunbar completes the graduated return-to-play protocol, having sustained a concussion last weekend.
Last week's starting back-row Cornell du Preez, lock Ben Toolis and prop Zander Fagerson move to the bench, where Fraser Brown - who recovered from a knee injury to join the squad this week - replaces fellow Glasgow Warriors hooker George Turner.
Townsend added: "Scotland's recent history against Australia has been one of close-fought matches and, after a couple of narrow defeats, we managed to record a win last June out in Sydney.
"Our players have been training hard and will draw on all they've learned in the games against Samoa and New Zealand to rise to the challenge of this final Autumn Test."
1 Darryl Marfo (Edinburgh Rugby)
2 Stuart McInally (Edinburgh Rugby)
3 Simon Berghan (Edinburgh Rugby)
4 Grant Gilchrist (Edinburgh Rugby)
5 Jonny Gray (Glasgow Warriors)
6 John Barclay CAPTAIN (Scarlets)
7 Hamish Watson (Edinburgh Rugby)
8 Ryan Wilson VICE CAPTAIN (Glasgow Warriors)
16 Fraser Brown (Glasgow Warriors)
17 Jamie Bhatti (Glasgow Warriors)
18 Zander Fagerson (Glasgow Warriors)
19 Ben Toolis (Edinburgh Rugby)
20 Cornell du Preez (Edinburgh Rugby)
21 Henry Pyrgos (Glasgow Warriors)
22 Peter Horne (Glasgow Warriors)
23 Byron McGuigan (Sale Sharks)