Marsh comes into the squad in place of paceman Chadd Sayers, who did not feature in Australia's two opening Test wins over England.
Steve Smith's Australians wrapped up a 120-run victory over the tourists in the second, day-night Adelaide Test, leaving them just one win away from retrieving the urn off England.
Selectors brought in West Australian Marsh, brother of Adelaide Test centurion Shaun Marsh, to offer pace back-up to the front-line fast-bowling attack of Mitchell Starc, Josh Hazlewood and Pat Cummins.
Mitchell Marsh last played a Test on Australia's tour of India in March and required a full shoulder reconstruction after an injury in the Bangalore Test.
The return of Marsh to the Australian set-up may spell trouble for struggling batsman Peter Handscomb.
Handscomb has scores of 14, 36 and 12 in the Ashes series so far, and in his past 10 first-class matches has 498 runs at 27.67.
Paceman Jackson Bird has been retained in the Test squad as the first reserve fast bowler.
The third Test gets underway at Perth's WACA Ground on December 14.
Steve Smith (capt), David Warner, Cameron Bancroft, Usman Khawaja, Peter Handscomb, Mitchell Marsh, Shaun Marsh, Tim Paine, Mitchell Starc, Pat Cummins, Josh Hazlewood, Nathan Lyon, Jackson Bird