"Unfortunately pulling out of @rolandgarros this year," the American posted on Instagram.
"I'm just about back to practicing normal (haven't had any issues for weeks) but played it super safe with recovery & return to play.
"If I had another 5-7 days I would have been there 100%."
Pegula, 30, has not played an official match since the Billie Jean King Cup in mid-April.
She then withdrew from the Madrid Open after "hurting herself", without giving any further details on the nature of her injury.
She also missed the Rome Open, the last big clay-court tournament prior to Roland Garros.
Pegula, however, is confident she will soon return to competition.
"I will definitely be back for a full grass season and the rest of the summer and grinding out the rest of the year," she posted.
Last year, Pegula, 30, was eliminated in the third round of the French Open by Belgium's Elise Mertens.
Her best result at Roland Garros is a quarter-final appearance in 2022 when she lost to eventual winner Iga Swiatek.
The draw for the French Open, which begins at the weekend, takes place later on Thursday.
