The deal, which closed Tuesday, values KKW Beauty at $1 billion, FOX Business previously reported.
Earlier this summer, Coty disclosed plans to acquire a portion of the company and further develop its global business.
Kardashian West, known from the long-running reality TV show “Keeping Up with the Kardashians,” founded KKW Beauty in 2017 and tapped into her hundreds of millions of social media followers to sell lip gloss, body foundation and perfume.
Together, the TV reality star and Coty will work on expanding beyond existing product lines and enter into new beauty categories, including a skincare line slated to launch in fiscal year 2022, the companies announced in a joint statement.
Kardashian West will still promote KKW Beauty using her "global reach capabilities through social media" while also helping with the development of new products.
Meanwhile, Coty will oversee the overall development of its skincare, haircare, personal care and nail products.
"She has a unique ability to read the latest beauty and wellness trends, while we have the expertise on global product positioning, access to a vast global distribution network, and the resources to enter new beauty categories," Coty CEO Sue Nabi said in a statement.
The products will be sold at "leading luxury beauty retailers" as well as online.
The Associated Press contributed to this report.