The 20-year-old Andreescu -- currently ranked No. 7 in the world -- announced her decision on social media, saying she wants to "focus on my health and training."
"I have come to the difficult decision to skip the clay court swing this year and will be taking the remainder of the season off to focus on my health and training," she wrote Tuesday on Twitter. "As hard as it was to come to this conclusion, I have so much to look forward to in 2021, including the Olympics.
"I want to use this time to focus on my game so I can come back stronger and better than ever. As always, your encouraging words and support meant the world to me and I look forward to getting back on the court and competing for Canada next year!"
Andreescu hasn't competed on tour since withdrawing from a match during the WTA Finals in October 2019 because of a left knee injury. The same knee ailment prevented her from playing at the Australian Open in January.
Andreescu -- the first Canadian to win a major singles trophy with her triumph in New York last year -- also skipped this month's U.S. Open, citing "unforeseen challenges" surrounding the coronavirus pandemic and a lack of preparation time.
The 2020 French Open is set to begin Sunday in Paris. Andreescu is the third top-10 player on the women's side to opt out of the tournament, joining No. 1 Ashleigh Barty and No. 3 Naomi Osaka.