# 1940 United States Senate elections

The 1940 United States Senate elections coincided with the election of Franklin D. Roosevelt to his third term as president. The 32 seats of Class 1 were contested in regular elections, and special elections were held to fill vacancies.
Although Roosevelt was re-elected, support for his administration had dropped somewhat after eight years, and the Republican opposition gained three seats from the Democrats. However, the New Deal Democrats regained firm control of both the House and Senate because Progressives dominated the election. The Minnesota Farmer–Labor Party also disappeared from the Senate, as Henrik Shipstead joined the Republican party and Ernest Lundeen had died during the preceding term. Senator Harry S. Truman of Missouri was elected to his final term in the Senate in 1940. Truman resigned in 1945 to serve as President Roosevelt's third Vice President.
Republicans later gained an additional seat through an appointment in Colorado.

## Gains, losses, and holds
### Retirements

One Republican and two Democrats retired instead of seeking re-election. One Republican retired instead of seeking election to finish the unexpired term.
| State | Senator | Replaced by |
| Maine | Frederick Hale | Owen Brewster |
| Ohio | Vic Donahey | Harold H. Burton |
| Vermont (special) | Ernest W. Gibson Jr. | George Aiken |
| Washington | Lewis B. Schwellenbach | Monrad Wallgren |

### Defeats

Five Democrats and two Republicans sought re-election but lost in the primary or general election. One Democrat sought election to finish the unexpired term but lost in the general election.
| State | Senator | Replaced by |
| Arizona | Henry F. Ashurst | Ernest McFarland |
| Delaware | John G. Townsend Jr. | James M. Tunnell |
| Illinois | James M. Slattery | C. Wayland Brooks |
| Indiana | Sherman Minton | Raymond E. Willis |
| Nebraska | Edward R. Burke | Hugh A. Butler |
| North Dakota | Lynn Frazier | William Langer |
| Utah | William H. King | Abe Murdock |
| West Virginia | Rush Holt Sr. | Harley M. Kilgore |

### Post-election changes

| State | Senator | Replaced by |
| Nevada | Key Pittman | Berkeley L. Bunker |
| Arkansas | John E. Miller | G. Lloyd Spencer |
| Colorado | Alva B. Adams | Eugene Donald Millikin |
| South Carolina | James F. Byrnes | Alva M. Lumpkin |
| South Carolina | Alva M. Lumpkin | Roger C. Peace |
| South Carolina | Roger C. Peace | Burnet R. Maybank |
| Texas | Morris Sheppard | Andrew Jackson Houston |
| Texas | Andrew Jackson Houston | W. Lee O'Daniel |
| Mississippi | Pat Harrison | James Eastland |
| Mississippi | James Eastland | Wall Doxey |
| West Virginia | Matthew M. Neely | Joseph Rosier |

### Party switches

One Farmer-Labor senator was re-elected as a Republican.
| State | Senator | Replaced by |
| Minnesota | Henrik Shipstead | Henrik Shipstead |

## Change in composition
### Before the elections

| | | D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ |
| D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ | D$_{10}$ | D$_9$ |
| D$_{19}$ | D$_{20}$ | D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ |
| D$_{38}$ | D$_{37}$ | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ | D$_{30}$ | D$_{29}$ |
| D$_{39}$ | D$_{40}$ | D$_{41}$ | D$_{42}$ | D$_{43}$ | D$_{44}$ | D$_{45}$ Ariz. Ran | D$_{46}$ Conn. Ran | D$_{47}$ Fla. Ran | D$_{48}$ Ill. (sp) Ran |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{49}$ Ind. Ran |
| D$_{58}$ N.M. Ran | D$_{57}$ Nev. Ran | D$_{56}$ Neb. Ran | D$_{55}$ Mont. Ran | D$_{54}$ Mo. Ran | D$_{53}$ Miss. Ran | D$_{52}$ Mass. Ran | D$_{51}$ Md. Ran | D$_{50}$ Ky. (sp) Ran | D$_{49}$ Ind. Ran |
| D$_{59}$ N.Y. Ran | D$_{60}$ Ohio Ran | D$_{61}$ Pa. Ran | D$_{62}$ R.I. Ran | D$_{63}$ Tenn. Ran | D$_{64}$ Texas Ran | D$_{65}$ Utah Ran | D$_{66}$ Va. Ran | D$_{67}$ Wash. Retired | D$_{68}$ W.Va. Ran |
| R$_{19}$ Maine Retired | R$_{20}$ Mich. Ran | R$_{21}$ N.J. Ran | R$_{22}$ N.D. Ran | R$_{23}$ Vt. (reg) Ran | R$_{24}$ Vt. (sp) Retired | FL$_1$ Minn. Ran | P$_1$ Wis. Ran | I$_1$ | D$_{69}$ Wyo. Ran |
| R$_{18}$ Idaho (sp) Ran | R$_{17}$ Del. Ran | R$_{16}$ Calif. Ran | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ | R$_{10}$ | R$_9$ |
| | | R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ |

### Election results

| | | D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ |
| D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ | D$_{10}$ | D$_9$ |
| D$_{19}$ | D$_{20}$ | D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ |
| D$_{38}$ | D$_{37}$ | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ | D$_{30}$ | D$_{29}$ |
| D$_{39}$ | D$_{40}$ | D$_{41}$ | D$_{42}$ | D$_{43}$ | D$_{44}$ | D$_{45}$ Ariz. Hold | D$_{46}$ Conn. Re-elected | D$_{47}$ Fla. Re-elected | D$_{48}$ Ky. (sp) Elected |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{49}$ Md. Re-elected |
| D$_{58}$ R.I. Re-elected | D$_{57}$ Pa. Re-elected | D$_{56}$ N.Y. Re-elected | D$_{55}$ N.M. Re-elected | D$_{54}$ Nev. Re-elected | D$_{53}$ Mont. Re-elected | D$_{52}$ Mo. Re-elected | D$_{51}$ Miss. Re-elected | D$_{50}$ Mass. Re-elected | D$_{49}$ Md. Re-elected |
| D$_{59}$ Tenn. Re-elected | D$_{60}$ Texas Re-elected | D$_{61}$ Utah Hold | D$_{62}$ Va. Re-elected | D$_{63}$ Wash. Hold | D$_{64}$ W.Va. Hold | D$_{65}$ Wyo. Re-elected | D$_{66}$ Del. Gain | I$_1$ | P$_1$ Wis. Re-elected |
| R$_{19}$ Mich. Re-elected | R$_{20}$ N.J. Re-elected | R$_{21}$ N.D. Hold | R$_{22}$ Vt. (reg) Re-elected | R$_{23}$ Vt. (sp) Hold | R$_{24}$ Ill. (sp) Gain | R$_{25}$ Ind. Gain | R$_{26}$ Minn. Re-elected under different party | R$_{27}$ Neb. Gain | R$_{28}$ Ohio Gain |
| R$_{18}$ Maine Hold | R$_{17}$ Idaho (sp) Elected | R$_{16}$ Calif. Re-elected | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ | R$_{10}$ | R$_9$ |
| | | R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ |
| Key | D$_#$ Democratic FL$_#$ Farmer–Labor P$_#$ Progressive R$_#$ Republican I$_#$ Independent |

## Race summaries
### Special elections during the 76th Congress

In these special elections, the winner elected during 1940 and seated once qualified; ordered by election date.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Idaho (Class 2) | John Thomas | Republican | 1928 (appointed) 1928 (special) 1932 (lost) 1940 (appointed) | Interim appointee elected November 5, 1940. | ▌Y John Thomas (Republican) 53.0% ▌Glen H. Taylor (Democratic) 47.0% |
| Illinois (Class 2) | James M. Slattery | Democratic | 1939 (appointed) | Interim appointee lost election to finish term. New senator elected November 5, 1940. Republican gain. | ▌Y C. Wayland Brooks (Republican) 50.1% ▌James M. Slattery (Democratic) 49.6% |
| Kentucky (Class 2) | Happy Chandler | Democratic | 1939 (appointed) | Interim appointee elected November 5, 1940. | ▌Y Happy Chandler (Democratic) 58.3% ▌Walter B. Smith (Republican) 41.7% |
| Vermont (Class 3) | Ernest W. Gibson Jr. | Republican | 1940 (appointed) | Interim appointee retired. New senator elected November 5, 1940. Republican hold. | ▌Y George Aiken (Republican) 61.6% ▌Herbert B. Comings (Democratic) 38.4% |

### Races leading to the 77th Congress

In these regular elections, the winners were elected for the term beginning January 3, 1941; ordered by state.
All of the elections involved the Class 1 seats.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Arizona | Henry F. Ashurst | Democratic | 1912 1916 1922 1928 1934 | Incumbent lost renomination. New senator elected. Democratic hold. | ▌Y Ernest McFarland (Democratic) 71.6% ▌I. A. Jennings (Republican) 28.0% ▌A. Walter Gehres (Prohibition) 0.4% |
| California | Hiram Johnson | Republican | 1916 1922 1928 1934 | Incumbent re-elected. | ▌Y Hiram Johnson (Republican) 82.5% ▌Fred Dyster (Prohibition) 13.5% ▌Anita Whitney (Communist) 3.6% |
| Connecticut | Francis T. Maloney | Democratic | 1934 | Incumbent re-elected. | ▌Y Francis T. Maloney (Democratic) 53.2% ▌Paul L. Cornell (Republican) 45.7% |
| Delaware | John G. Townsend Jr. | Republican | 1928 1934 | Incumbent lost re-election. New senator elected. Democratic gain. | ▌Y James M. Tunnell (Democratic) 50.6% ▌John G. Townsend Jr. (Republican) 47.3% ▌William F. Allen (Liberal Democratic) 2.1% |
| Florida | Charles O. Andrews | Democratic | 1936 (special) | Incumbent re-elected. | ▌Y Charles O. Andrews (Democratic) Unopposed |
| Indiana | Sherman Minton | Democratic | 1934 | Incumbent lost re-election. New senator elected. Republican gain. | ▌Y Raymond E. Willis (Republican) 50.5% ▌Sherman Minton (Democratic) 49.1% ▌Carl W. Thompson (Prohibition) 0.3% ▌John H. Kingsbury (Socialist) 0.1% |
| Maine | Frederick Hale | Republican | 1916 1922 1928 1934 | Incumbent retired. New senator elected. Republican hold. | ▌Y Owen Brewster (Republican) 58.6% ▌Louis J. Brann (Democratic) 41.3% |
| Maryland | George L. P. Radcliffe | Democratic | 1934 | Incumbent re-elected. | ▌Y George L. P. Radcliffe (Democratic) 64.7% ▌Harry Nice (Republican) 33.5% |
| Massachusetts | David I. Walsh | Democratic | 1918 1924 (lost) 1926 (special) 1928 1934 | Incumbent re-elected. | ▌Y David I. Walsh (Democratic) 55.6% ▌Henry Parkman Jr. (Republican) 42.8% |
| Michigan | Arthur Vandenberg | Republican | 1928 (appointed) 1928 (special) 1928 1934 | Incumbent re-elected. | ▌Y Arthur Vandenberg (Republican) 52.7% ▌Frank Fitzpatrick (Democratic) 47.0% |
| Minnesota | Henrik Shipstead | Farmer–Labor | 1922 1928 1934 | Incumbent re-elected as a Republican. Republican gain. | ▌Y Henrik Shipstead (Republican) 53.0% ▌Elmer A. Benson (Farmer–Labor) 25.7% ▌John E. Regan (Democratic) 20.6% |
| Mississippi | Theodore G. Bilbo | Democratic | 1934 | Incumbent re-elected. | ▌Y Theodore G. Bilbo (Democratic) Unopposed |
| Missouri | Harry S. Truman | Democratic | 1934 | Incumbent re-elected. | ▌Y Harry S. Truman (Democratic) 51.2% ▌Manvel H. Davis (Republican) 48.7% ▌W. F. Rinck (Socialist) 0.1% ▌Theodore Baeff (Socialist Labor) 0.01% |
| Montana | Burton K. Wheeler | Democratic | 1922 1928 1934 | Incumbent re-elected. | ▌Y Burton K. Wheeler (Democratic) 73.4% ▌E. K. Cheadle (Republican) 26.6% |
| Nebraska | Edward R. Burke | Democratic | 1934 | Incumbent lost renomination. New senator elected. Republican gain. | ▌Y Hugh A. Butler (Republican) 57.0% ▌Robert Leroy Cochran (Democratic) 41.5% |
| Nevada | Key Pittman | Democratic | 1913 (special) 1916 1922 1928 1934 | Incumbent re-elected. Winner died November 10, 1940, and Berkeley L. Bunker (D) was appointed both to finish the term and to start the next term. | ▌Y Key Pittman (Democratic) 60.5% ▌Samuel Platt (Republican) 39.5% |
| New Jersey | W. Warren Barbour | Republican | 1931 (appointed) 1932 (special) 1936 (lost) 1938 (special) | Incumbent re-elected. | ▌Y W. Warren Barbour (Republican) 55.1% ▌James H. R. Cromwell (Democratic) 44.1% |
| New Mexico | Dennis Chávez | Democratic | 1935 (appointed) 1936 (special) | Incumbent re-elected. | ▌Y Dennis Chávez (Democratic) 56.0% ▌Albert K. Mitchell (Republican) 44.1% |
| New York | James M. Mead | Democratic | 1938 (special) | Incumbent re-elected. | ▌Y James M. Mead (Democratic) 53.3% ▌Bruce Fairchild Barton (Republican) 46.7% |
| North Dakota | Lynn Frazier | Republican/ Nonpartisan League | 1922 1928 1934 | Incumbent lost renomination. New senator elected. Republican hold. | ▌Y William Langer (Republican-NPL) 38.1% ▌William Lemke (Independent) 35.1% ▌Charles V. Vogel (Democratic) 26.5% |
| Ohio | Vic Donahey | Democratic | 1934 | Incumbent retired. New senator elected. Republican gain. | ▌Y Harold H. Burton (Republican) 52.4% ▌John McSweeney (Democratic) 47.6% |
| Pennsylvania | Joseph F. Guffey | Democratic | 1934 | Incumbent re-elected. | ▌Y Joseph F. Guffey (Democratic) 51.8% ▌Jay Cooke (Republican) 47.4% |
| Rhode Island | Peter G. Gerry | Democratic | 1916 1922 1928 (lost) 1934 | Incumbent re-elected. | ▌Y Peter G. Gerry (Democratic) 55.2% ▌James O. McManus (Republican) 44.8% |
| Tennessee | Kenneth McKellar | Democratic | 1916 1922 1928 1934 | Incumbent re-elected. | ▌Y Kenneth McKellar (Democratic) 70.8% ▌Howard Baker Sr. (Republican) 29.2% |
| Texas | Tom Connally | Democratic | 1928 1934 | Incumbent re-elected. | ▌Y Tom Connally (Democratic) 94.3% ▌George I. Shannon (Republican) 5.7% |
| Utah | William H. King | Democratic | 1916 1922 1928 (lost) 1934 | Incumbent lost renomination. New senator elected. Democratic hold. | ▌Y Abe Murdock (Democratic) 62.9% ▌Philo Farnsworth (Republican) 37.2% |
| Vermont | Warren Austin | Republican | 1931 (special) 1934 | Incumbent re-elected. | ▌Y Warren Austin (Republican) 66.5% ▌Ona S. Searles (Democratic) 33.6% |
| Virginia | Harry F. Byrd | Democratic | 1933 (appointed) 1933 (special) 1934 | Incumbent re-elected. | ▌Y Harry F. Byrd (Democratic) 93.3 |
| Washington | Lewis B. Schwellenbach | Democratic | 1934 | Incumbent retired. New senator elected. Democratic hold. Incumbent resigned December 16, 1940. Winner appointed to finish the term. | ▌Y Monrad Wallgren (Democratic) 54.2% ▌Stephen F. Chadwick (Republican) 45.8% |
| West Virginia | Rush Holt Sr. | Democratic | 1934 | Incumbent lost renomination. New senator elected. Democratic hold. | ▌Y Harley M. Kilgore (Democratic) 56.3% ▌Thomas Sweeney (Republican) 43.7% |
| Wisconsin | Robert M. La Follette Jr. | Progressive | 1925 (special) 1928 1934 | Incumbent re-elected. | ▌Y Robert M. La Follette Jr. (Progressive) 45.3% ▌Fred H. Clausen (Republican) 41.4% ▌James E. Finnegan (Democratic) 13.2% |
| Wyoming | Joseph C. O'Mahoney | Democratic | 1933 (appointed) 1934 | Incumbent re-elected. | ▌Y Joseph C. O'Mahoney (Democratic) 58.7% ▌Milward Simpson (Republican) 41.3% |

## Closest races

Thirteen races had a margin of victory under 10%:
| State | Party of winner | Margin |
| Illinois | Republican (flip) | 0.7% |
| Indiana | Republican (flip) | 1.4% |
| Missouri | Democratic | 2.5% |
| North Dakota | Republican | 3.0% |
| Delaware | Democratic (flip) | 3.3% |
| Wisconsin | Progressive | 3.9% |
| Pennsylvania | Democratic | 4.4% |
| Ohio | Republican (flip) | 4.8% |
| Michigan | Republican | 5.7% |
| Idaho (special) | Republican | 5.9% |
| New York | Democratic | 6.6% |
| Connecticut | Democratic | 7.5% |
| Washington | Democratic | 8.4% |
There is no tipping point state.

## Arizona

1940 United States Senate election in Arizona :
| Party | Party | Candidate | Votes | % |
| | Democratic | Ernest McFarland | 101,495 | 71.6 |
| | Republican | Irving A. Jennings Sr. | 39,657 | 28 |
| | Prohibition | A. Walter Gehres | 579 | 0.4 |
| Majority | Majority | Majority | 61,838 | 43.63 |
| Turnout | Turnout | Turnout | 141,731 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## California

United States Senate election in California of 1940 :
| Party | Party | Candidate | Votes | % |
| | Republican | Hiram W. Johnson (Incumbent) | 2,238,899 | 82.50 |
| | Prohibition | Fred Dyster | 366,044 | 13.49 |
| | Communist | Anita Whitney | 97,478 | 3.59 |
| | Write-In | John Anson Ford | 7,415 | 0.27 |
| | None | Scattering | 4,029 | 0.15 |
| Majority | Majority | Majority | 1,872,855 | 69.01 |
| Turnout | Turnout | Turnout | 2,713,865 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Connecticut

1940 United States Senate election in Connecticut :
| Party | Party | Candidate | Votes | % |
| | Democratic | Francis T. Maloney (Incumbent) | 416,740 | 53.15 |
| | Republican | Paul L. Cornell | 358,313 | 45.70 |
| | Socialist | Kenneth W. Thurlow | 6,557 | 0.84 |
| | Socialist Labor | James A. Hutchin | 1,343 | 0,17 |
| | Communist | Isadore Wofsy | 1,114 | 0,14 |
| Majority | Majority | Majority | 58,427 | 12.45 |
| Turnout | Turnout | Turnout | 784,067 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Delaware

1940 United States Senate election in Delaware :
| Party | Party | Candidate | Votes | % |
| | Democratic | James M. Tunnell | 68,294 | 50.63 |
| | Republican | John G. Townsend Jr. (Incumbent) | 63,799 | 47.30 |
| | Independent Democratic | William F. Allen | 2,786 | 2.07 |
| Majority | Majority | Majority | 4,495 | 3.33 |
| Turnout | Turnout | Turnout | 134,879 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Florida

1940 United States Senate election in Florida :
| Party | Party | Candidate | Votes | % |
| | Democratic | Charles O. Andrews (Incumbent) | 323,216 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Idaho (special)

1940 United States Senate special election in Idaho :
| Party | Party | Candidate | Votes | % |
| | Republican | John Thomas | 124,535 | 52.96 |
| | Democratic | Glen H. Taylor | 110,614 | 47.04 |
| Majority | Majority | Majority | 13,921 | 5.92 |
| Turnout | Turnout | Turnout | 235,149 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Illinois (special)

1940 United States Senate special election in Illinois :
| Party | Party | Candidate | Votes | % |
| | Republican | Charles W. Brooks | 2,045,924 | 50.07 |
| | Democratic | James M. Slattery (Incumbent) | 2,025,097 | 49.56 |
| | Prohibition | Enoch A. Holtwick | 8,625 | 0.21 |
| | Socialist | Clarence H. Mayer | 6,517 | 0.16 |
| | None | Scattering | 16 | 0.00 |
| Majority | Majority | Majority | 20,827 | 0.51 |
| Turnout | Turnout | Turnout | 4,086,179 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Indiana

1940 United States Senate election in Indiana :
| Party | Party | Candidate | Votes | % |
| | Republican | Raymond E. Willis | 888,070 | 50.45 |
| | Democratic | Sherman Minton (Incumbent) | 864,803 | 49.13 |
| | Prohibition | Carl W. Thompson | 5,621 | 0.32 |
| | Socialist | John H. Kingsbury | 1,751 | 0.10 |
| Majority | Majority | Majority | 23,267 | 1.32 |
| Turnout | Turnout | Turnout | 1,760,245 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Kentucky (special)

1940 United States Senate special election in Kentucky :
| Party | Party | Candidate | Votes | % |
| | Democratic | Happy Chandler (Incumbent) | 561,151 | 58.27 |
| | Republican | Walter B. Smith | 401,812 | 41.73 |
| Majority | Majority | Majority | 159,339 | 16.54 |
| Turnout | Turnout | Turnout | 962,963 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Maine

1940 United States Senate election in Maine :
| Party | Party | Candidate | Votes | % |
| | Republican | Ralph Owen Brewster | 150,149 | 58.61 |
| | Democratic | Louis J. Brann | 105,740 | 41.27 |
| | Independent | Lewis Gordon | 305 | 0.12 |
| Majority | Majority | Majority | 44,409 | 17.34 |
| Turnout | Turnout | Turnout | 256,194 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Maryland

1940 United States Senate election in Maryland :
| Party | Party | Candidate | Votes | % |
| | Democratic | George L. P. Radcliffe (Incumbent) | 394,239 | 64.74 |
| | Republican | Harry W. Nice | 203,912 | 33.48 |
| | Socialist | Edwin B. Abbott | 4,204 | 0.69 |
| | Independent | David L. Elliott | 3,423 | 0.56 |
| | American Labor | Robert Kadish | 1,848 | 0.30 |
| | Communist | Albert E. Blumberg | 1,349 | 0.22 |
| Majority | Majority | Majority | 190,327 | 31.26 |
| Turnout | Turnout | Turnout | 608,975 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Massachusetts

1940 United States Senate election in Massachusetts :
| Party | Party | Candidate | Votes | % |
| | Democratic | David I. Walsh (Incumbent) | 1,088,838 | 55.64 |
| | Republican | Henry Parkman Jr. | 838,122 | 42.38 |
| | Prohibition | George L. Thompson | 9,632 | 0.49 |
| | Communist | Philip Frankfeld | 9,465 | 0.48 |
| | Socialist | Lyman Paine | 6,876 | 0.35 |
| | Socialist Labor | Horace I. Hillis | 4,133 | 0.21 |
| Majority | Majority | Majority | 250,716 | 12.82 |
| Turnout | Turnout | Turnout | 1,957,089 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Michigan

1940 United States Senate election in Michigan :
| Party | Party | Candidate | Votes | % |
| | Republican | Arthur Vandenberg (Incumbent) | 1,053,104 | 52.65 |
| | Democratic | Frank FitzGerald | 939,740 | 46.98 |
| | Socialist | Nahum Burnett | 3,580 | 0.18 |
| | Communist | Elmer Johnson | 2,290 | 0.11 |
| | Prohibition | Carroll P. Pahman | 937 | 0.05 |
| | Socialist Labor | Theos A. Grove | 691 | 0.03 |
| Majority | Majority | Majority | 113,364 | 5.67 |
| Turnout | Turnout | Turnout | 2,000,342 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Minnesota

1940 United States Senate election in Minnesota :
| Party | Party | Candidate | Votes | % |
| | Republican | Henrik Shipstead (Incumbent) | 641,049 | 53.00 |
| | Farmer–Labor | Elmer Austin Benson | 310,875 | 25.70 |
| | Democratic | John E. Regan | 248,658 | 20.56 |
| | Trotskyist Anti-War | Grace Holmes Carlson | 8,761 | 0.72 |
| | Independent | Carl Winter | 256 | 0.02 |
| Majority | Majority | Majority | 330,174 | 27.30 |
| Turnout | Turnout | Turnout | 1,209,599 | |
| | Republican gain from Farmer–Labor | Republican gain from Farmer–Labor | Republican gain from Farmer–Labor | Republican gain from Farmer–Labor |

## Mississippi

1940 United States Senate election in Mississippi :
| Party | Party | Candidate | Votes | % |
| | Democratic | Theodore G. Bilbo (Incumbent) | 143,431 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Missouri

One-term Democrat Harry S. Truman was narrowly re-elected. He would only serve until resigning January 17, 1945, to become U.S. Vice President.
1940 Missouri United States Senate election :
| Party | Party | Candidate | Votes | % |
| | Democratic | Harry S. Truman (Incumbent) | 930,775 | 51.17 |
| | Republican | Manvel H. Davis | 886,376 | 48.73 |
| | Socialist | W.F. Rinck | 1,669 | 0.09 |
| | Socialist Labor | Theodore Baeff | 196 | 0.01 |
| Majority | Majority | Majority | 44,499 | 2.44 |
| Turnout | Turnout | Turnout | 1,819,016 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Montana

1940 United States Senate election in Montana :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Burton K. Wheeler (Incumbent) | 176,753 | 73.43 | +3.29% |
| | Republican | E. K. Cheadle | 63,941 | 26.57 | −2.17% |
| Majority | Majority | Majority | 112,812 | 46.87 | +5.47% |
| Turnout | Turnout | Turnout | 240,694 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Nebraska

1940 United States Senate election in Nebraska :
| Party | Party | Candidate | Votes | % |
| | Republican | Hugh A. Butler | 340,250 | 57.00 |
| | Democratic | Robert Leroy Cochran | 247,659 | 41.49 |
| | None | Albert F. Ruthven | 8,982 | 1.50 |
| Majority | Majority | Majority | 92,591 | 15.51 |
| Turnout | Turnout | Turnout | 596,891 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Nevada

Pittman suffered a severe heart attack just before the election on November 5, and two doctors told his aides before the election that death was imminent. To avoid affecting the election, the party told the press that the senator was hospitalized for exhaustion and that his condition was not serious. Pittman died on November 10 at the Washoe General Hospital in Reno, Nevada. Governor Edward Carville would go on to appoint Berkeley L. Bunker as his replacement.
In later years, a myth spread that Pittman had in fact died before the election, and his body had been kept on ice in the Mizpah Hotel in Tonopah so that Carville could appoint his replacement.
1940 United States Senate election in Nevada :
| Party | Party | Candidate | Votes | % |
| | Democratic | Key Pittman (Incumbent) | 31,351 | 60.48 |
| | Republican | Samuel Platt | 20,488 | 39.52 |
| Majority | Majority | Majority | 10,863 | 20.96 |
| Turnout | Turnout | Turnout | 51,839 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New Jersey

1940 United States Senate election in New Jersey :
| Party | Party | Candidate | Votes | % |
| | Republican | W. Warren Barbour (Incumbent) | 1,029,331 | 55.11 |
| | Democratic | James H. R. Cromwell | 823,893 | 44.11 |
| | Socialist | McAlister Coleman | 8,836 | 0.47 |
| | Independent | James A. Tumulty Jr. | 2,784 | 0.15 |
| | Communist | Mary Ellen Dooner | 1,519 | 0.08 |
| | Prohibition | Edson R. Leach | 645 | 0.03 |
| | Socialist Labor | Harry Santhouse | 464 | 0.02 |
| | Socialist Workers | George Breitman | 303 | 0.02 |
| Majority | Majority | Majority | 225,438 | 11.00 |
| Turnout | Turnout | Turnout | 1,867,775 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## New Mexico

1940 United States Senate election in New Mexico :
| Party | Party | Candidate | Votes | % |
| | Democratic | Dennis Chávez (Incumbent) | 103,194 | 55.95 |
| | Republican | Albert K. Mitchell | 81,257 | 44.05 |
| Majority | Majority | Majority | 21,937 | 11.90 |
| Turnout | Turnout | Turnout | 184,451 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New York

The whole ticket nominated by Democrats and American Laborites was elected.
1940 United States Senate election in New York :
| Party | Party | Candidate | Votes | % |
| | Democratic | James M. Mead | 2,893,407 | 47.06 |
| | American Labor | James M. Mead | 381,359 | 6.20 |
| | Total | James M. Mead (Incumbent) | 3,274,766 | 53.26 |
| | Republican | Bruce Barton | 2,842,942 | 46.66 |
| | Prohibition | Stephen W. Paine | 4,944 | 0.08 |
| Total votes | Total votes | Total votes | 6,148,562 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## North Dakota

1940 United States Senate election in North Dakota :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | William Langer | 100,647 | 38.11% | −20.13% |
| | Independent | William Lemke | 92,593 | 35.06% | — |
| | Democratic | Charles J. Vogel | 69,847 | 26.45% | −13.80% |
| | Independent | Jasper Haaland | 1,1014 | 0.38% | — |
| Majority | Majority | Majority | 8,054 | 3.05% | −14.95% |
| Turnout | Turnout | Turnout | 259,607 | | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Ohio

1940 United States Senate election in Ohio :
| Party | Party | Candidate | Votes | % |
| | Republican | Harold H. Burton | 1,602,498 | 52.37 |
| | Democratic | John McSweeney | 1,457,304 | 47.63 |
| Majority | Majority | Majority | 145,194 | 4.74 |
| Turnout | Turnout | Turnout | 3,059,802 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Pennsylvania

General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Joseph F. Guffey (Incumbent) | 2,069,980 | 51.79 | +1.01% |
| | Republican | Jay Cooke | 1,893,104 | 47.36 | −0.90% |
| | Socialist | David H.H. Felix | 15,449 | 0.39 | 0.00% |
| | Prohibition | H. B. Mansell | 11,113 | 0.28 | −0.40% |
| | Communist | Carl Reeve | 4,761 | 0.12 | −0.09% |
| | Socialist Labor | Frank Knotek | 2,503 | 0.06 | −0.10% |
| | N/A | Other | 110 | 0.00 | N/A |
| Majority | Majority | Majority | 176,876 | 4.43 | |
| Turnout | Turnout | Turnout | 3,997,020 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Rhode Island

1940 United States Senate election in Rhode Island :
| Party | Party | Candidate | Votes | % |
| | Democratic | Peter G. Gerry (Incumbent) | 173,927 | 55.16 |
| | Republican | James O. McManus | 141,401 | 44.84 |
| Majority | Majority | Majority | 32,526 | 10.32 |
| Turnout | Turnout | Turnout | 315,328 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Tennessee

1940 United States Senate election in Tennessee :
| Party | Party | Candidate | Votes | % |
| | Democratic | Kenneth McKellar (Incumbent) | 295,440 | 70.80 |
| | Republican | Howard Baker Sr. | 121,790 | 29.19 |
| | Independent | John Randolph Neal Jr. | 35.06 | 0.01 |
| Majority | Majority | Majority | 173,650 | 41.61 |
| Turnout | Turnout | Turnout | 417,265 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Texas

1940 United States Senate election in Texas :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tom Connally (Incumbent) | 978,095 | 94.24 |
| | Republican | George I. Shannon | 59,340 | 5.72 |
| | Communist | Homer Brooks | 408 | 0.04 |
| Majority | Majority | Majority | 918,755 | 88.52 |
| Turnout | Turnout | Turnout | 1,037,843 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Utah

1940 United States Senate election in Utah :
| Party | Party | Candidate | Votes | % |
| | Democratic | Abe Murdock | 155,499 | 62.85 |
| | Republican | Philo Farnsworth | 91,931 | 37.15 |
| Majority | Majority | Majority | 63,568 | 25.70 |
| Turnout | Turnout | Turnout | 247,430 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Vermont

There were 2 elections due to the June 20, 1940, death of two-term Republican Ernest Willard Gibson.

### Vermont (regular)

Two-term Republican Warren Austin was easily re-elected. He faced no opponents in the primary.
Vermont regular election :
| Party | Party | Candidate | Votes | % |
| | Republican | Warren Austin (Incumbent) | 93,283 | 66.4 |
| | Democratic | Ona S. Searles | 47,101 | 33.6 |
| Total votes | Total votes | Total votes | 140,384 | 100.0 |
| Majority | Majority | Majority | 46,182 | 32.9 |
| Total votes | Total votes | Total votes | 140,388 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |
Austin served only until his August 2, 1946, resignation to become U.S. Ambassador to the United Nations.

### Vermont (special)

Gibson's son, Republican Ernest W. Gibson Jr. was appointed June 24, 1940, to continue his father's term, pending a special election, in which he was not a candidate.
Vermont special election :
| Party | Party | Candidate | Votes | % |
| | Republican | George Aiken | 87,150 | 61.6 |
| | Democratic | Herbert B. Comings | 54,263 | 38.4 |
| Majority | Majority | Majority | 32,887 | 23.20 |
| Total votes | Total votes | Total votes | 141,413 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |
Aiken did not take the seat until January 10, 1941, as he wanted to remain Governor of Vermont. He would be repeatedly re-elected and serve until his 1975 retirement.

## Virginia

1940 United States Senate election in Virginia :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Harry F. Byrd Sr. (Incumbent) | 274,260 | 93.32 | +17.36% |
| | Independent | Hilliard Berstein | 11,159 | 3.80 | |
| | Independent | Alice Burke | 8,250 | 2.81 | |
| | Write-ins | | 212 | 0.07 | +0.05% |
| Majority | Majority | Majority | 263,101 | 89.53 | +34.50% |
| Turnout | Turnout | Turnout | 293,881 | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Washington

1940 United States Senate election in Washington :
| Party | Party | Candidate | Votes | % |
| | Democratic | Monrad Wallgren | 404,718 | 54.16 |
| | Republican | Stephen F. Chadwick | 342,589 | 45.84 |
| Majority | Majority | Majority | 62,129 | 8.32 |
| Turnout | Turnout | Turnout | 747,307 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## West Virginia

1940 United States Senate election in West Virginia :
| Party | Party | Candidate | Votes | % |
| | Democratic | Harley M. Kilgore | 492,413 | 56.33 |
| | Republican | Thomas Sweeney | 381,806 | 43.67 |
| Majority | Majority | Majority | 110,607 | 12.66 |
| Turnout | Turnout | Turnout | 874,219 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Wisconsin

1940 United States Senate election in Wisconsin :
| Party | Party | Candidate | Votes | % |
| | Progressive | Robert M. La Follette Jr. (Incumbent) | 605,609 | 45.26 |
| | Republican | Fred H. Clausen | 553,692 | 41.38 |
| | Democratic | James E. Finnegan | 176,688 | 13.20 |
| | Independent Communist | Ted Furman | 1,308 | 0.10 |
| | Socialist Labor | Adolf Wiggert Jr. | 838 | 0.06 |
| Majority | Majority | Majority | 51,917 | 4.88 |
| Turnout | Turnout | Turnout | 1,338,135 | |
| | Progressive hold | Progressive hold | Progressive hold | Progressive hold |

## Wyoming

1940 United States Senate election in Wyoming :
| Party | Party | Candidate | Votes | % |
| | Democratic | Joseph C. O'Mahoney (Incumbent) | 65,022 | 58.74 |
| | Republican | Milward L. Simpson | 45,682 | 41.26 |
| Majority | Majority | Majority | 19,340 | 17.48 |
| Turnout | Turnout | Turnout | 110,704 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |