Susan Kay Quatro (born June 3, 1950) is an American singer, bass guitarist, songwriter, and actress. In the 1970s, she scored a string of singles that found success in Europe and Australia, with both "Can the Can" (1973) and "Devil Gate Drive" (1974) reaching number one in several countries.

Quatro released her self-titled debut album in 1973. Since then, she has released 15 studio albums, 10 compilation albums, and one live album. Other songs, including "48 Crash", "Daytona Demon", "The Wild One", and "Your Mama Won't Like Me", also charted highly overseas. Following a recurring role as bass player Leather Tuscadero on the popular American sitcom Happy Days, her duet "Stumblin' In" with Smokie's lead singer Chris Norman reached number four in the US, her only song to chart in the top 40 in her homeland.

Between 1973 and 1980, Quatro was awarded six Bravo Ottos, an award given to musicians as voted in the German teen magazine Bravo. In 2010, she was voted into the Michigan Rock and Roll Legends online Hall of Fame. She is reported to have sold over 50 million records worldwide, and continues to perform live. Quatro's most recent studio album, Face to Face, was released in 2023 and follows the 2021 collaboration The Devil in Me with her son Richard Tuckey, who had already taken part in No Control in 2019. Quatro also remains active in radio broadcasting.