She won the 2019 Lou Marsh Trophy on Monday after becoming the first Canadian to win a Grand Slam singles title, defeating Serena Williams in the Open final.
The 19-year-old soared to a No. 5 ranking after starting the year at No. 152. She also won at Indian Wells, California, and earned more than $6.5 million for the season.
"I can't wait for what 2020 will bring and am always proud to represent Canada at the highest level," she said.
She beat out golfer Brooke Henderson, sprinter Andre De Grasse, Atlanta Braves pitcher Mike Soroka and St. Louis Blues goaltender Jordan Binnington.
The winner of the Toronto Star award is selected annually by a panel of Canadian sports journalists. The trophy has been awarded annually since 1936 with a three-year gap during World War II.