| Election Name: | 1956 United States Senate election in Missouri |
| Country: | Missouri |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1950 United States Senate election in Missouri |
| Previous Year: | 1950 |
| Next Election: | 1960 United States Senate special election in Missouri |
| Next Year: | 1960 (special) |
| Image1: | Thomas Carey Hennings.jpg |
| Nominee1: | Thomas C. Hennings Jr. |
| Party1: | Democratic Party (US) |
| Popular Vote1: | 1,015,936 |
| Percentage1: | 56.41% |
| Nominee2: | Herbert Douglas |
| Party2: | Republican Party (US) |
| Popular Vote2: | 785,048 |
| Percentage2: | 43.59% |
| Map Size: | 270px |
| U.S. senator | |
| Before Election: | Thomas C. Hennings Jr. |
| Before Party: | Democratic Party (US) |
| After Election: | Thomas C. Hennings Jr. |
| After Party: | Democratic Party (US) |
The 1956 United States Senate election in Missouri took place on November 6, 1956 in Missouri. The incumbent Democratic Senator, Thomas C. Hennings Jr., was re-elected. He defeated Republican nominee Herbert Douglas, winning 56.4% of the vote. Hennings outperformed Democratic presidential nominee Adlai Stevenson II, who won 50.1% in the presidential election in Missouri.