Frank John Viola Jr. is an American former starting pitcher in Major League Baseball who played for the Minnesota Twins (1982–1989), New York Mets (1989–1991), Boston Red Sox (1992–1994), Cincinnati Reds (1995), and Toronto Blue Jays (1996). A three-time All-Star, he was named World Series MVP with the Twins in 1987 and won the AL Cy Young Award in 1988. He is the pitching coach of the High Point Rockers.
He batted and threw left-handed, and he was nicknamed "Sweet Music" – a nickname he picked up after a Minnesota sports writer declared that when Viola pitched, there was "Sweet Music" in the Hubert H. Humphrey Metrodome. The nickname was a play on the fact that his last name is also a name of a musical instrument, although pronounced differently.