The unseeded 20th-ranked Keys was leading her semi-final rival Liudmila Samsonova 5-7 7-5 3-0 at Memorial Drive on Friday when the Russian withdrew due to an abdominal injury.
Keys, 29, progressed to Saturday's final where she will meet good friend and top-seeded compatriot Jessica Pegula.
Pegula downed Kazakhstan's Yulia Putintseva 7-6(4) 6-3 in Friday night's later semi-final.
Keys won the Adelaide event in 2022 and has extremely fond memories of Melbourne Park's Australian Open, where she has appeared in two semi-finals, a quarter-final, and two fourth rounds.
Keys is also a Brisbane International finalist and a past semi and quarter-finalist at the Sydney International.
"It's unique because we actually are coming (to Australia) with time off, so we're always a little bit fresh," she said.
"And I always really enjoy it here. Typically the courts play pretty fast here and I've always really liked that.
"And I don't know, I just always felt really great playing in Australia.
"I kind of lean into that, and being able to have as much success as I have had here, I just feel quite comfortable on a lot of these courts."
Madison Keys moves into the final as Samsonova retires.— wta (@WTA) Final Score: 5-7, 7-5, 3-0 RET.#AdelaideTennis pic.twitter.com/J0kaYWG9tbJanuary 10, 2025
Keys said the comfort in her Australian surroundings was again paying dividends.
"I'm playing pretty well," said the Illinois-born right-hander.
"Serving got me out of some tricky spots today which is always a good sign.
"We worked on a lot of different things during the off season and my goal was really to just try to start putting those things into matches when it matters.
"Keeping that as the focus has been why I've been able to continue playing well."
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