| Election Name: | 1956 United States Senate election in Washington |
| Country: | Washington |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1950 United States Senate election in Washington |
| Previous Year: | 1950 |
| Next Election: | 1962 United States Senate election in Washington |
| Next Year: | 1962 |
| Election Date: | November 6, 1956 |
| Nominee1: | Warren Magnuson |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 685,565 |
| Percentage1: | 61.09% |
| Nominee2: | Arthur B. Langlie |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 436,652 |
| Percentage2: | 38.91% |
| Map Size: | 250px |
| U.S. Senator | |
| Before Election: | Warren Magnuson |
| Before Party: | Democratic Party (United States) |
| After Election: | Warren Magnuson |
| After Party: | Democratic Party (United States) |
The 1956 United States Senate election in Washington was held on November 6, 1956. Incumbent Democratic U.S. Senator Warren Magnuson won a third term in office, defeating Republican nominee Arthur B. Langlie.
The blanket primary was held on September 18, 1956.