James Tedesco returns as Australia's starting fullback against Fiji, his first Kangaroos appearance in three years.
He will captain the side, with regular skipper Isaah Yeo rested.
David Fifita, Sam Walker, Blayke Brailey and Bradman Best make their Australia debuts in Sunday's match at Suncorp Stadium.
Fifita, 26, previously played four Tests for Tonga at the 2022 World Cup. A move from the Gold Coast Titans to South Sydney under Wayne Bennett helped revive his career.
Walker earned his first Australian start after a Sydney Roosters premiership and a strong Queensland State of Origin debut.
Mitchell Moses' leg injury in last week's 24-22 win over New Zealand gives Walker a chance to claim the No.7 jersey for the rest of the tournament.
Brailey and Best were key figures in NSW's 2-1 Origin series victory.
Australia's reshaped pack includes front-rowers Keaon Koloamatangi and Lindsay Smith, with Cameron Murray at No.13.
Tonga can secure a semi-final place by beating Lebanon on Friday. Kulikefu Finefeuiaki debuts at the World Cup, while Sione Katoa and Paul Alamoti make their first starts.
Samoa's Sua Fa'alogo starts against Papua New Guinea after scoring four tries against France. Deine Mariner is out with a hamstring injury.
England have kept the same 19 for France after losing 30-12 to Tonga. They need a substantial win to retain remote semi-final hopes.
New Zealand start Keano Kini at fullback against Cook Islands, with Kalyn Ponga injured. Tanner Stowers-Smith and Jacob Laban make their Test debuts from the bench.
Cook Islands welcome back fullback Valentine Holmes, who missed their loss to Fiji with an ankle injury.