The Danish star, who has never been past the quarter-finals at the Parisian grand slam tournament, has been struggling with an injury to her right ankle for several weeks.
She had hoped to take part in the second major of the year, however, but pulled out of the tournament on Tuesday afternoon, with the official Roland Garros Twitter feed sharing the news.
Stan Wawrinka climbs to world number four, Rafa Nadal down to 10
Wozniacki's injury was sustained when she rolled her ankle in practice ahead of WTA Istanbul last month.
At the time she promised to be "back soon", but the issue has proven more persistent than expected.
Before her injury she had not been playing well, and performed poorly at Miami and Indian Wells.
Wozniacki also pulled out of recent clay-court tournaments in Madrid and Rome as she has battled injury.
Her ranking has now slipped to 34th in the world.
At the same time, world number eight - Switzerland's Belinda Bencic - has also had to pull out of the competition due to back injury which has troubled her since March.