Scott Vincent James Baio (/ˈbeɪ.oʊ/; born September 22, 1960 or 1961 (sources differ)) 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), and for playing 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 guest-starred on various television programs, appeared in several independent films, and starred on the Nickelodeon sitcom See Dad Run (2012–2015).
Baio was born in the Bay Ridge neighborhood of the Brooklyn borough of New York City, the son of Italian immigrants from Castellammare del Golfo, Sicily, Italy; Rose, a homemaker, and Mario Baio, who worked as his manager. He graduated from Xaverian High School.