Former captain Ritchie returns for Scotland against Australia
The Edinburgh flanker, deposed as both skipper and regular starter this year, returns after Glasgow back-row Jack Dempsey was ruled out with an injury sustained in a defeat by world champions South Africa a fortnight ago.
Scotland coach Gregor Townsend has selected what appears to be his strongest available XV as the Dark Blues go in search of a major scalp in their final Test of the year after pushing the Springboks hard before losing 32-15 at Murrayfield.
Scott Cummings returns to the second-row after a one-match ban, while Townsend can field his preferred back three of Blair Kinghorn at full-back and Darcy Graham and Duhan van der Merwe on the wings for the first time since last year's World Cup.
Glasgow's Tom Jordan, who has impressed at full-back, drops to the bench as part of a 5-3 split between forwards and backs.
Scotland (15-1)
Blair Kinghorn; Darcy Graham, Huw Jones, Sione Tuipulotu (capt), Duhan van der Merwe; Finn Russell, Ben White; Matt Fagerson, Rory Darge, Jamie Ritchie; Scott Cummings, Grant Gilchrist; Zander Fagerson, Ewan Ashman, Pierre Schoeman
Replacements: Dylan Richardson, Rory Sutherland, Will Hurd, Alex Craig, Josh Bayliss, George Horne, Tom Jordan, Kyle Rowe
Coach: Gregor Townsend (SCO)