The 1964 United States Senate elections were held on November 3. The 33 seats of Class 1 were contested in regular elections. Special elections were also held to fill vacancies. They coincided with the election of President Lyndon B. Johnson by an overwhelming majority, to a full term. His Democratic Party picked up a net two seats from the Republicans. As of 2022, this was the last time either party has had a two-thirds majority in the Senate, which would have hypothetically allowed the Senate Democrats to override a veto, propose constitutional amendments, or convict and expel certain officials without any votes from Senate Republicans. In practice, however, internal divisions effectively prevented the Democrats from doing so. The Senate election coincided with Democratic gains in the House in the same year.
The 1964 United States Senate election in Hawaii took place on November 3, 1964.
The 1986 United States Senate election in California took place on November 4, 1986. Incumbent Democratic U.S. Senator Alan Cranston narrowly won re-election to a fourth and final term over Republican U.S. Congressman Ed Zschau.
The 1980 United States Senate election in California took place on November 4, 1980. Incumbent Democrat U.S. Senator Alan Cranston easily won re-election to a third term, even as the state's former Republican governor, Ronald Reagan, won a landslide victory in the concurrent presidential election, and a target of the National Conservative Political Action Committee.
The 1932 United States Senate election in California was held on November 2, 1932. Incumbent Republican Senator Samuel Morgan Shortridge ran for a third term in office, but lost a highly competitive four-way Republican primary to Tallant Tubbs, who ran as a "wet" or anti-prohibition candidate.
The 1938 United States Senate election in California was held on November 2, 1938. Incumbent Democratic Senator William Gibbs McAdoo ran for a second term, but was defeated by Sheridan Downey in the Democratic primary. Downey went on to defeat Philip Bancroft in the general election.
The 1952 United States Senate election in California was held on November 4, 1952.
The 1956 United States Senate election in California was held on November 6, 1956.
The 1954 United States Senate special election in California was held on November 2, 1954, to elect a U.S. Senator to complete the unexpired term of Senator Richard Nixon, who resigned on becoming Vice President of the United States following the 1952 presidential election. Incumbent Republican U.S. Senator Thomas Kuchel, who had been appointed by Governor Earl Warren, won election to the remainder of the term, defeating Democratic nominee Sam Yorty.
The 1916 United States Senate election in California was held on November 6, 1916. Incumbent Senator John Downey Works did not run for re-election.
The 1922 United States Senate election in California was held on November 7, 1922. Incumbent Republican Senator Hiram Johnson was re-elected to his second term in office.
The 1928 United States Senate election in California was held on November 6, 1928. Incumbent Republican Senator Hiram Johnson was re-elected to his third term in office. He defeated Democrat Minor Moore and Prohibition Party nominee Los Angeles City Councilman Charles H. Randall.
The United States Senate election of 1934 in New Jersey was held on November 6, 1934.
The 1934 United States Senate election in California was held on November 6, 1934. Incumbent Republican Senator Hiram Johnson was re-elected to his fourth term in office.
The United States Senate elections of 1936 in New Jersey was held on November 3, 1936.
The 1940 United States Senate election in Wisconsin was held on November 5, 1940.
The 1944 United States Senate election in California was held on November 7, 1944.
The two 1946 United States Senate elections in California were held concurrently on November 5, 1946.
The 1964 United States Senate election in California was held on November 3, 1964.
The 2021 New Jersey State Senate election was held on November 2, 2021. New Jersey voters elected state senators in all of the state's legislative districts for a two-year term to the New Jersey Senate. This was the first election since 1991 where Republicans net gained state Senate seats.
