French Open champion and No.1 seed Barty will come up against two-time grand slam winners Osaka and Petra Kvitova, along with No.7 seed Belinda Bencic in the Red Group.
Barty was announced as the winner of the Race to Shenzhen ahead of Karolina Pliskova and hopes to celebrate by being crowned champion in her singles debut at the season-ending tournament in China.
"It was already an honour to qualify for the WTA Finals, but to also finish the Race to Shenzhen on top is an achievement I'm incredibly proud of," the Australian said.
"This is a special tournament for myself and my team and I’ll be fighting hard to finish the WTA season with the Shenzhen title."
Pliskova will take on defending champion Elina Svitolina, along with Simona Halep and Bianca Andreescu in the Purple Group.
US Open champion Andreescu and 22-year-old Swiss Bencic will be making their debuts in the tournament.
Osaka and Kvitova meet in the first match of the event on Sunday.