Following her straight sets victory over her sister, Venus Williams, she revealed she was pregnant during the tournament. She took off to give birth to her first child, Alexis Olympia in September.
Williams will return with a match against the French Open champion Jelena Ostapenko. They will be the first women to compete in the event.
"I am delighted to be returning to the court in Abu Dhabi for the first time since the birth of my daughter," Williams said in a statement.
"The Mubadala World Tennis Championship has long marked the beginning of the men's global tennis season and I am excited and honoured to be making my comeback as part of the first women to participate in the event."
Williams can equal Margaret Court's record of 24 Grand Slam titles if she defends her title in Australia. But she will start the quest with a low seeding after slipping to 22nd in the rankings.
The six-strong men's field in Abu Dhabi features the former world number one Novak Djokovic, who will also be making his comeback.
The 12-time Grand Slam champion has not played competitively since his quarter-final loss in July to Tomas Berdych at Wimbledon because of an elbow injury.