1956 United States Senate elections

Colored shading indicates party with largest share of that row.

Parties					Total
		Democratic	Republican	Other
Before these elections		49	47	0	96
Not up		31	30	—	61
	Class 1 (1952)	11	20	—	31
	Class 2 (1954)	20	10	—	30
Up		18	17	—	35
	Class 3 (1950→1956)	15	17	—	32
	Special: Class 1	1	0	—	1
	Special: Class 2	2	0	—	2
Incumbent retired		5	1	—	6
	Held by same party	2	0	—	2
	Replaced by other party	1 Republican replaced by 1 Democrat 3 Democrats replaced by 3 Republicans		—	4
	Result	3	3	0	6
Incumbent ran		13	16	—	29
	Won re-election	12	13	—	25
	Lost re-election	3 Republicans replaced by 3 Democrats 1 Democrat replaced by 1 Republican		—	4
	Lost renomination but held by same party	0	0	—	0
	Result	15	14	0	29
Total elected		18	17	0	35
Net change					0
Nationwide vote		23,291,351[a]	22,219,450	406,207	45,917,008
	Share	50.72%	48.39%	0.88%	100%
Result		49	47	0	96

Source: Clerk of the U.S. House of Representatives^[1]

One Republican and five Democrats retired instead of seeking re-election.

Three Republicans and one Democrat sought re-election but lost in the general election.

One Republican was appointed to the seat of a deceased Democrat. Two Democrats won special elections, one seat was previously held by a Democrat and another by a Republican. One Democrat was appointed to replace another Democrat.

In these special elections, the winners were seated during 1956 or in 1957 before January 3; ordered by election date, then state.

In these regular elections, the winners were elected for the term beginning January 3, 1957; ordered by state.

All of the elections involved the Class 3 seats.

Fifteen races had a margin of victory under 10%:

Two elections in Kentucky converted both seats from Democratic to Republican. As a result, this marked the first time since 1916 that both Senate seats in a state flipped from one party to the other in a single election cycle.

1956 United States Senate special election in Kentucky

← 1954 November 6, 1956 1960 →

Nominee John Sherman Cooper Lawrence Wetherby Party Republican Democratic Popular vote 538,505 473,140 Percentage 53.23% 46.77%

County results Sherman:      50-60%      60-70%      70–80%      80–90% Wetherby:      50–60%      60–70%      70–80%

U.S. senator before election Robert Humphreys Democratic Elected U.S. Senator John Sherman Cooper Republican

Following the death of Alben Barkley on April 30, 1956, Robert Humphreys was appointed June 21, 1956 to continue the term, pending a special election.^[2] Humphreys did not run in the special election to finish the term that would end in 1961.

Republican former-senator John Sherman Cooper, who had twice won special elections to that seat in 1946 and 1952, was again elected to finish the term.

This time, however, Cooper would be re-elected in 1960 and again in 1966, serving until his 1973 retirement.

1956 United States Senate election in Kentucky

← 1950 November 6, 1956 1962 →

Nominee Thruston Ballard Morton Earle Clements Party Republican Democratic Popular vote 506,903 499,922 Percentage 50.35% 49.65%

County results Morton:      50–60%      60–70%      70–80%      80–90% Clements:      50–60%      60–70%      70–80%      80–90%

U.S. senator before election Earle Clements Democratic Elected U.S. Senator Thruston Ballard Morton Republican

First-term Democrat Earle Clements lost re-election to Republican Thruston B. Morton, who was Eisenhower's Assistant Secretary of State for Legislative Affairs.

1956 United States Senate election in New York

← 1950 November 6, 1956 1962 →

Nominee Jacob Javits Robert F. Wagner Jr. Party Republican Democratic Alliance Liberal Popular vote 3,723,933 3,265,159 Percentage 53.27% 46.71%

County results Javits:      50–60%      60–70%      70–80% Wagner:      50–60%      60–70%

U.S. senator before election Herbert H. Lehman Democratic Elected U.S. Senator Jacob Javits Republican

In New York, the Republican state convention met on September 10 at Albany, New York, and nominated New York State Attorney General Jacob K. Javits.^[3] The Democratic state convention met on September 10 at Albany, New York, and nominated Mayor of New York City Robert F. Wagner Jr., for the U.S. Senate.^[4] The Liberal Party endorsed the Democratic nominee, Mayor Robert F. Wagner Jr., for the U.S. Senate.^[5] On October 1, a movement was launched to vote for General of the Army Douglas MacArthur as a write-in candidate for the U.S. Senate.^[6] On October 2, MacArthur disavowed the campaign, and stated that he was not a candidate.^[7]

The Republican candidate was elected.

1956 United States Senate election in North Dakota

← 1950 November 6, 1956 1962 →

Nominee Milton Young Quentin Burdick Party Republican Democratic–NPL Popular vote 155,305 87,919 Percentage 63.61% 36.01%

County results Young:      40-50%      50-60%      60-70%      70-80%      80-90%

U.S. senator before election Milton Young Republican Elected U.S. Senator Milton Young Republican

In North Dakota, the incumbent, Republican Milton Young, sought and received re-election to his third term, defeating North Dakota Democratic-NPL Party candidate Quentin N. Burdick, son of North Dakota congressman Usher L. Burdick.^[8]

Only Young filed as a Republican, and the endorsed Democratic candidate was Quentin Burdick, the son of well-known politician Usher Burdick, and former candidate for Governor of North Dakota. Young and Burdick won the primary elections for their respective parties.

One independent candidate, Arthur C. Townley, also filed before the deadline. Townley would later seek the state's other senate seat in 1958, and was known for creating the National Non-Partisan League.

1956 United States Senate election in Oregon

← 1950 November 7, 1956 1962 →

Nominee Wayne Morse Douglas McKay Party Democratic Republican Popular vote 396,849 335,405 Percentage 54.20% 45.80%

County results Morse:      50–60%      60–70% McKay:      50-60%

Senator before election Wayne Morse Democratic Elected Senator Wayne Morse Democratic

In Oregon, Republican-turned-Independent-turned-Democrat Wayne Morse decided to seek re-election for his first full term as a Democrat. Morse defeated Republican candidate Douglas McKay in the hotly contested general election.^[9]

1956 United States Senate election in Pennsylvania

← 1950 November 6, 1956 1962 →

Nominee Joseph S. Clark Jr. James H. Duff Party Democratic Republican Popular vote 2,268,641 2,250,671 Percentage 50.08% 49.69%

County results Clark Jr.:      50–60%      60–70% Duff:      40–50%      50–60%      60–70%      70–80%

U.S. senator before election James H. Duff Republican Elected U.S. Senator Joseph S. Clark, Jr. Democratic

In Pennsylvania, incumbent Republican U.S. senator James H. Duff sought re-election to another term, but was defeated by the Democratic nominee, Joseph S. Clark Jr.

In South Carolina the regular election was held simultaneously with the special election.

1956 United States Senate election in South Carolina

← 1950 November 6, 1956 1962 →

Nominee Olin D. Johnston Leon P. Crawford Party Democratic Republican Popular vote 230,150 49,695 Percentage 82.21% 17.75%

County results Johnston:      50–60%      60–70%      70–80%      80–90%      >90%

U.S. senator before election Olin D. Johnston Democratic Elected U.S. Senator Olin D. Johnston Democratic

Incumbent Democrat Olin D. Johnston handily defeated Republican mayor of Clemson Leon P. Crawford. Olin D. Johnston, the incumbent Senator, faced no opposition from South Carolina Democrats and avoided a primary election. Leon P. Crawford, the mayor of the town of Clemson in the Upstate, faced no opposition from South Carolina Republicans and avoided a primary election. Crawford campaigned as a defender of states' rights and denounced Johnston for backing the New Deal and the Fair Deal. The state Republican Party believed that Crawford could have a chance in the election if he galvanized the 128,000 registered black voters, although they were weary of being labeled as the black party. In the end, Johnston remained highly popular with the voters who were still leery of the Republican party and he easily defeated Crawford in the general election.

The special election resulted from the resignation of Senator Strom Thurmond on April 4, 1956, who was keeping a campaign pledge he had made in the 1954 election. Thurmond was unopposed in his bid to complete the remaining four years of the term. Senator Strom Thurmond faced no opposition from South Carolina Democrats and avoided a primary election. There was a possibility that Governor George Bell Timmerman Jr. might enter the race, but Thurmond was held in such high regard by the voters that there would have been no chance of defeating Thurmond. With no challenge to the remainder of the term, Thurmond did not conduct a campaign and rejoined his old law firm in Aiken until he returned to the Senate after the general election.

1956 United States Senate election in Vermont

← 1950 November 6, 1956 (1956-11-06) 1962 →

Nominee George Aiken Bernard O'Shea Party Republican Democratic Popular vote 103,101 52,184 Percentage 66.39% 33.61%

County results Aiken:      50–60%      60–70%      70–80%      80–90%

U.S. senator before election George Aiken Republican Elected U.S. Senator George Aiken Republican

In Vermont, incumbent Republican George Aiken ran successfully for re-election to another term in the United States Senate, defeating Democratic challenger Bernard G. O'Shea.