Keechant Sewell, 49, is a 23-year veteran of the Nassau Police Department in nearby Long Island, where she became chief of detectives in September 2020.
For Mr Adams, the move fulfils a campaign pledge to name a female commissioner.
The NYPD is the largest police force in the US.
Speaking to media on Wednesday morning, Mr Adams - a former NYPD captain- said that women often are "sitting on the bench" and "never allowed to get in the game" when it comes to policing.
"That is stopping today," he said.