"Don't Mess with Bill" is a song by the American band The Marvelettes, released in 1963. The track features a catchy melody and lyrics that convey a message about loyalty and standing up for a friend named Bill, who is being mistreated by others. The song showcases the Motown sound, characterized by its upbeat rhythm and harmonious vocals. It became popular on the Billboard Hot 100 chart, further solidifying the Motown label's influence in the music industry during the 1960s. The Marvelettes were known for their contributions to the girl group genre, and this song is one of their memorable hits.