The 1936 United States Senate election in Mississippi was held on November 3, 1936. Incumbent Democratic U.S. Senator Pat Harrison was re-elected to a fourth term in office.
Because Harrison faced no opposition in the general election, his victory in the August 25 primary was tantamount to election.
Incumbent Senator Pat Harrison received a primary challenge from Martin S. Conner, the Governor of Mississippi. Conner's campaign was supported by Theodore G. Bilbo, the other U.S. Senator from Mississippi. Stuart C. Broom, a former ally and law partner of Bilbo, supported Harrison's reelection.
Time reported that support from Broom, who was nicknamed "Clean Sweep", was important to the Harrison campaign, with Broom routinely making a speech "which brought down the house wherever he delivered it.