The Romanian, twice a Grand Slam champion, said she had undergone surgery for functional and aesthetic reasons after suffering with breathing difficulties.
"I could never do it before because I never found the necessary three months for the recovery," she posted on Twitter alongside a photo of her with a bandaged nose.
"I felt like it was the right time to do it and also to do something for me as a person. That is why I also did the aesthetic part, that I wanted to do for a long time as I did not like my nose at all.
"I know many of you can understand me."
Halep said she did not know how long she would be out.
"I am not thinking of anything else but recovery," she said.
"What is sure is won't compete again this year."
Halep could return in time for the Australian Open, a tournament she finished a runner up back in 2018.
