Erdogan made the announcement while delivering a speech in the capital of Ankara on Wednesday but gave no other details. He did not say when or how the woman was captured or identify her by name.
Al-Baghdadi was known to have four wives.
Erdogan’s announcement comes just days after Turkish forces captured al-Baghdadi’s elder sister, identified as Rasmiya Awad, in northwestern Syria. She was with her husband, daughter-in-law and five children when she was detained.
Erdogan says: “We caught his wife, but we didn’t make a fuss about it. I am announcing this today for the first time.”