UFC 42: Sudden Impact was a mixed martial arts event held by the Ultimate Fighting Championship on April 25, 2003, at American Airlines Arena in Miami, Florida. The event was broadcasted live on pay per view in the United States, and later released on DVD.
UFC 42 was the first UFC event to take place in Florida. Headlining the event was a Welterweight Title bout between Matt Hughes and Sean Sherk. UFC 42 also marked the first UFC appearance for Rich Franklin.