Coach Jay Tregonning has included Dallinger and 18-year-old fullback Faitala Moleka in the starting side for the Allianz Stadium clash while her Brumbies teammates Tabua Tuinakauvadra and Jasmin Huriwai are included on the bench for the first time.
Dallinger will partner NSW Waratahs No.9 Layne Morgan in the halves.
Long-time captain Shannon Parry will line up for her final Test match in her trademark position at openside flanker.
Fellow flanker Piper Duck, who will succeed Parry as skipper, wasn't considered for the match due to a foot injury.
"It's been a bittersweet mix of emotions, working towards my final Test match," Parry said.
"I'm welcoming the opportunity to lead out the Wallaroos one last time - I'm glad the match is on home soil, where I can mark this occasion with my partner, family and friends.
"Going up against Fijiana is always a physical contest, but we've been preparing for that.
"The girls can't wait to rip in and kick off the 2023 season with a strong performance."
Tregonning said there was "fierce competition" for each spot and he'd been impressed by the standard at training.
"The girls worked hard to earn their places in the starting XV," he said.
"There's a good mix of emerging and established talent in the team, and I'm looking forward to Saturday's contest."
Wallaroos veteran Grace Hamilton has maintained her place at No.8, with Waratahs teammate Layne Morgan to start at halfback.
Wallaroos: Bree-Anna Cheatham, Adiana Talakai, Eva Karpani, Michaela Leonard, Annabelle Codey, Ashley Marsters, Shannon Parry (capt), Grace Hamilton, Layne Morgan, Carys Dallinger, Ivania Wong, Cecilia Smith, Georgina Friedrichs, Maya Stewart, Faitala Moleka. Reserves: Tania Naden, Emily Robinson, Bridie O'Gorman, Sera Naiqama, Tabua Tuinakauvadra, Jasmin Huriwai, Siokapesi Palu, Alana Elisaia.
