Australia opens its campaign against South Africa in Brisbane in eight days.
Among the new caps is wing Corey Toole, who has just returned from the Paris Olympic Games, where he was a member of the Australian team.
Also included are loose forwards Seru Uru, Luke Reimer and Carlo Tizzano, Hamish Stewart and Max Jorgensen.
Loose forward Charlie Cale and wing Darby Lancaster, who debuted during the July Tests, were omitted.
Fifty-nine Test wing Marika Koroibete, who plays in Japan for Saitama Wild Knights, is the only overseas-based player included.
Schmidt said, "There was plenty of discussion among the coaches, but we're hopeful that the squad selected will embrace the challenge of playing South Africa over the next fortnight.
"We know there's a lot of hard work to do ahead of those Test matches, and we're looking forward to getting back together as a group on Saturday and rolling up our sleeves.
"The players enjoyed the vocal support we received during the July Tests, and they will be looking to earn continued public support over the coming weeks."
The squad is:
Forwards: Allan Alaalatoa, Angus Bell, Angus Blyth, Matt Faessler, Nick Frost, Tom Hooper, Isaac Kailea, Josh Nasser, Zane Nonggorr, Billy Pollard, Luke Reimer, Lukhan Salakaia-Loto, James Slipper, Carlo Tizzano, Taniela Tupou, Seru Uru, Rob Valetini, Jeremy Williams, Harry Wilson.
Backs: Filipo Daugunu, Ben Donaldson, Josh Flook, Jake Gordon, Len Ikitau, Max Jorgensen, Andrew Kellaway, Marika Koroibete, Noah Lolesio, Tom Lynagh, Tate McDermott, Hunter Paisami, Dylan Pietsch, Hamish Stewart, Corey Toole, Nic White, Tom Wright.
Unavailable: Kurtley Beale, Langi Gleeson, Harry Johnson-Holmes, Bayley Kuenzle, Rob Leota, Lachlan Lonergan, Fraser McReight, David Porecki, Blake Schoupp, and Liam Wright.