Lincoln Rafael Díaz-Balart is a Cuban-American attorney and politician. He was the U.S. representative for Florida's 21st congressional district from 1993 to 2011. He is a member of the Republican Party. He previously served in the Florida House of Representatives and the Florida Senate. He retired from Congress in 2011 and his younger brother, Mario Díaz-Balart, who had previously represented Florida's 25th congressional district, succeeded him. He is currently chairman of the Congressional Hispanic Leadership Institute. After leaving Congress, he started a law practice and a consulting firm, both based in Miami, Florida.

Florida's 21st congressional district is a U.S. congressional district on the Treasure Coast. In the 2020 redistricting cycle, the district was drawn as a successor to the previous 18th district and contains all of St. Lucie County and Martin County as well as the northeastern part of Palm Beach County, and includes Port St. Lucie, Fort Pierce, Stuart, Jupiter, and Palm Beach Gardens, as well as Treasure Coast International Airport. The previous iteration of the 21st district, which extended from Delray Beach to Palm Beach, was instead renamed the 22nd district.