The 1948 United States Senate election in Louisiana was held on November 2, 1948. Incumbent Senator Allen J. Ellender was re-elected to a third term in office.
On August 31, Ellender won the Democratic primary with 61.7% of the vote. At this time, Louisiana was a one-party state, and the Democratic nomination was tantamount to victory. Ellender won the November general election without an opponent.