Interstate 4 (abbreviated I-4) is a 132.30-mile (212.91 km) intrastate Interstate Highway located entirely within the state of Florida, United States. It goes from Interstate 275 in Tampa, Florida ( ) to Interstate 95 at Daytona Beach, Florida ( ). It also has the Florida Department of Transportation designation of State Road 400, but only a small portion of the route is signed at the east end.

I-4 is currently the lowest-numbered Interstate Highway in the contiguous 48 U.S. states.

The combination of the Tampa, Lakeland, Orlando and Daytona Beach metropolitan areas is often referred to as the I-4 Corridor, since the freeway connects all four.