World number one and defending champion Serena Williams will face unseeded Italian Camila Giorgi in the first round of the Australian Open.

Giorgi is the highest ranked unseeded player at 35 in the WTA Tour, and looms as a potentially tricky opponent for Williams, who has endured a less-than-ideal preparation heading to the Australian Open, which gets underway on Monday.

Williams - boasting a 68-9 win-loss record at Melbourne Park - has not played since withdrawing from the Hopman Cup due to a knee injury over a week ago, but the 21-time grand slam champion has won the two previous encounters against Giorgi, though both were on clay.

If Williams navigates the opening rounds, a quarter-final showdown with world number five Maria Sharapova looms in a rematch of last year's decider on Rod Laver Arena.

Sharapova starts her campaign against Japan's Nao Hibino, while world number two Simona Halep, who appears to have shaken off an Achilles problem, will play a qualifier.

Notable first-round matches:
Serena Williams (1) v Camila Giorgi
Simona Halep (2) v Qualifier
Garbine Muguruza (3) v Anett Kontaveit
Agnieszka Radwanska (4) v Christina McHale
Maria Sharapova (5) v Nao Hibino
Petra Kvitova (6) v Qualifier
Belinda Bencic (12) v Alison Riske
Victoria Azarenka (14) v Alison Van Uytvanck
Madison Keys (15) v Zarina Diyas