| Election Name: | 1940 United States Senate election in New Jersey |
| Country: | New Jersey |
| Flag Year: | 1896 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1938 United States Senate special election in New Jersey |
| Previous Year: | 1938 (special) |
| Next Election: | 1944 United States Senate special election in New Jersey |
| Next Year: | 1944 (special) |
| Election Date: | November 5, 1940 |
| Image1: | William Warren Barbour.jpg |
| Nominee1: | William Warren Barbour |
| Party1: | Republican Party (US) |
| Popular Vote1: | 1,029,331 |
| Percentage1: | 55.11% |
| Party2: | Democratic Party (US) |
| Popular Vote2: | 823,893 |
| Percentage2: | 44.11% |
| Map Size: | 280px |
| Senator | |
| Before Party: | Republican Party (US) |
| After Party: | Republican Party (US) |
The United States Senate election of 1940 in New Jersey was held on November 5, 1940.
Incumbent Republican Senator William Warren Barbour was re-elected over Democrat James H. R. Cromwell, who had recently been appointed United States Ambassador to Canada.