Anett Kontaveit will face American tennis player Bernarda Pera in the first round of the competition to get her campaign underway.
The biggest shock of the day perhaps was the elimination of sixth seed Karolina Pliskova against unseeded Swiss player Jil Teichmann.
After the tournament was cancelled in 2020, Barty returned in 2021 and successfully defended her title.
The second round of the Australian Open saw two upsets in the women's singles as both Garbine Muguruza and Anett Kontaveit were eliminated.
Rybakina is fresh from reaching her eighth career final in Adelaide last week before falling to Ashleigh Barty in the title match.
This comes after the former World No.1 lost to Facundo Bagnis in his first match of the season last week in Melbourne.
Petra Kvitova had survived two match points in the final set to overcome Arantxa Rus, 3-6, 7-6, 7-5.
The No.6 seed from Spain defeated No.8 seed Anett Kontaveit of Estonia 6-3, 7-5 to capture her third and biggest title of the year.
Anett Kontaveit needed three sets to take down Maria Sakkari to reach the title match of the Akron WTA Finals Guadalajara, where she will play Garbine Muguruza.
No.4 seed Maria Sakkari clinched her spot in the semifinals of the Akron WTA Finals Guadalajara with a three-set win over Sabalenka.