The 23-time women's singles tennis champion will defend her Australian Open title, according to the tournament director.
Former world number one women's tennis player Serena Williams will return to the sport in January.
Williams, 36, has not competed since winning a 23rd Grand Slam singles championship at the 2017 Australian Open in January.
A knee injury, pregnancy, and marriage to internet entrepreneur Alexis Ohanian saw Williams take a year-long break from tennis.
But according to tournament director Craig Tiley, Williams has got her Visa, has officially entered the competition, and has already started practising for 2018.
"There's no question she'll be ready in our view," Tiley said, according to BBC Sport.
Williams has won the Australia Open seven times.