Scott Vincent James Baio (/?be?.o?/; born September 22, 1960) is an American actor and television director. He is known for his role as Chachi Arcola on the sitcom Happy Days (1977–1984) and its spin-off Joanie Loves Chachi (1982–1983), as well as the title character on the sitcom Charles in Charge (1984–1990), Dr. Jack Stewart in the medical-mystery-drama series Diagnosis: Murder (1993–1995), and the titular hero of the musical film Bugsy Malone (1976), his onscreen debut.
Baio has further appeared in various television programs as a guest star, several independent films, and starred on the Nickelodeon sitcom See Dad Run (2012–2015).