"Bad Girls" is a critically acclaimed 1979 single released by American singer Donna Summer. Co-written by Summer and the Brooklyn Dreams. The inspiration for her to write the song came after one of her assistants was offended by a police officer who thought she was a street prostitute. A rough version of the song had originally been written a couple of years before its release. Neil Bogart, upon hearing it, wanted Donna to give it to Cher for her upcoming album. Donna refused and put it away for a couple of years.

The song became a number-one hit on the Billboardpop, R&B and dance singles charts simultaneously becoming, alongside "Hot Stuff", her most successful single. The song helped the the album of the same name to reach the multi-platinum status in the United States. A 12" single of the song was released as a medley with "Hot Stuff". Although "Hot Stuff" was extended for the 12" single, "Bad Girls" remained in the 4:55 album version. A "Bad Girls" 12" single with a time of 6:55 was produced but never released commercially. A demo version of the song was released on the "Deluxe Edition" of the "Bad Girls" cd.