Mario Rafael Díaz-Balart y Caballero (born September 25, 1961) is an American politician serving as the U.S. representative for Florida's 26th congressional district. A member of the Republican Party, he was elected in 2002, and his district includes much of northwestern Miami-Dade County, including Hialeah, and much of the northern portion of the Everglades.

Díaz-Balart has been the dean of Florida's congressional delegation since April 2021.