After a year on the sidelines Casey O'Neill is back and ready to resume her charge to become Australia's next UFC champion.

The undefeated flyweight didn't fight in 2022 after undergoing a knee reconstruction but will be looking to claim her fifth straight UFC victory when she faces former title challenger Jennifer Maia at UFC 286 in London on Sunday.

Currently ranked 12th in the division, a victory would propel her into the top 10.

While it might be a little early to be talking about title shots, O'Neill is probably Australia's best chance at producing the country's first female UFC champion.

"I'm a better fighter than when I left and I'm excited to show it," O'Neill said.

"[Maia's] a good name to have on your resume; she's fought for the belt, she's fought a lot of people at the top and she's been around for a long, long time.

"I think that's a cool stamp to have on the resume so I'm excited to have a win over her.

"I think she'll fight me the same way she fights everyone. You watch one of her fights and you've seen it all. I'm excited to make it hard for her, to make her wish she never came to London."

O'Neill might have lost a little bit of shine during her year away but a dominant performance over Maia should put her firmly back in the mix.

The 25-year-old was counted as one of the rising stars of women's MMA on the back of her explosive start to life in the UFC and with women's flyweight host to a bevy of new stars like Talia Santos and Erin Branchfield, O'Neill said she's ready to remind everybody what they've been missing.

"I was that girl before I got injured, I was the person everyone was talking about," O'Neill said.

"Me going away gave other girls a chance to shine but I think it's great for the division, the work they've done has brought eyes to the division and got people talking. I'm super excited and I'm grateful they all had such a big year."

No result in the past 12 months showed the growth of women's flyweight like long-time champion Valentina Shevchenko's shock loss to Alex Grasso two weeks ago.

Grasso, a 6-1 underdog, submitted Shevchenko in the fourth to throw the door open for the new generation of fighters, a group O'Neill plans to be a part of.

"Everyone's getting better and the cream is rising to the top. It's a great time to be a flyweight. I thought she (Grasso) had an awesome game plan and she stayed patient and found her opportunity and cemented it," O'Neill said.

"Fighting someone like Valentina, I think a lot of people make it bigger in their head than it actually is, she was the champion for so long that every girl in the division was training for her in some kind of way, and I think Grasso stayed really composed.