David Conner Treen Sr. was an American politician and attorney from Louisiana. A member of the Republican Party, Treen served as U.S. Representative for Louisiana's 3rd congressional district from 1973 to 1980 and the 51st governor of Louisiana from 1980 to 1984. Treen was the first Republican elected to either office since Reconstruction.

Louisiana's 3rd congressional district is a United States congressional district in the U.S. state of Louisiana. The district covers the southwestern and south central portion of the state, ranging from the Texas border to the Atchafalaya River.