1934 United States Senate elections

The 1934 United States Senate elections were held in the middle of Democratic President Franklin D. Roosevelt's first term. The 32 seats of Class 1 were contested in regular elections, and special elections were held to fill vacancies. During the Great Depression, voters strongly backed Roosevelt's New Deal and his allies in the Senate, with Democrats picking up a net of nine seats, giving them a supermajority (which required 64 seats, two-thirds of the total 96 seats in 1934). Republicans later lost three more seats due to mid-term vacancies (one to Farmer-Labor and two to Democrats); however, a Democrat in Iowa died and the seat remained vacant until the next election. The Democrats entered the next election with a 70-22-2-1 majority.

This marked the second of three times since the ratification of the 17th Amendment in 1913 that the opposition party failed to flip any Senate seats in a midterm election, alongside 1914 and 2022.

A number of historic figures were first elected to the Senate in 1934, including future President Harry S. Truman, future Federal District Judge and Labor Secretary Lewis B. Schwellenbach, and future Supreme Court Justice Sherman Minton. This election cycle currently holds the record for the number of defeated non-presidential party incumbents, with eight.