The 1966 United States Senate election in Louisiana was held on November 8, 1966. Incumbent Democratic Senator Allen Ellender was elected to a sixth term in office.

1966 Democratic Senate primary election in Louisiana

← 1960 August 13, 1966 1972 →

Nominee Allen Ellender J. D. DeBlieux Troyce Guice Party Democratic Democratic Democratic Popular vote 494,619 94,154 78,137 Percentage 74.17% 14.12% 11.72%

Parish results Ellender:      50–60%      60–70%      70–80%      80–90%      >90% DeBlieux:      50–60%

U.S. senator before election Allen Ellender Democratic Elected U.S. Senator Allen Ellender Democratic

On August 13, Ellender won the Democratic primary with 74.17% 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.