The 22-time Grand Slam champion has not played a competitive match since bowing out in the second round of this year's Australian Open when hampered by a hip flexor problem.
Nadal was initially expected to miss just eight weeks but underwent surgery on a hip muscle in June.
"After a year away from competition, it's time to come back," Nadal said in a video posted to social media.
"It will be in Brisbane, the first week of January. I'll see you there."
Last month, Australian Open tournament director Craig Tiley confirmed that Nadal would be participating in the year's first Grand Slam.
Nadal has said he expects to retire after the 2024 season, with a series of injuries limiting his appearances on Tour.
He dropped out of the top 100 for the first time in 20 years earlier in the season and has slipped to number 633 in the world but is eligible for a protected ranking having been injured and not competing in any event for at least six months.
Nadal has previously expressed a desire to play one more French Open and represent Spain at the Paris Olympics next year before retiring at the end of his 23rd season on the tour.
The Brisbane tournament, which is returning after a three-year hiatus forced initially by the COVID pandemic, will run from December 31st to January 7th.
The Australian Open takes place at Melbourne Park from January 14th-28th.
Nadal's last Australian Open victory came in 2022 when he beat Russia's Daniil Medvedev and became the first man in the Open era to come back from two sets down in the final to win.
