| Election Name: | 1986 United States Senate election in Washington |
| Country: | Washington |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1980 United States Senate election in Washington |
| Previous Year: | 1980 |
| Next Election: | 1992 United States Senate election in Washington |
| Next Year: | 1992 |
| Election Date: | November 3, 1986 |
| Image1: | File:Brockman Adams (cropped).jpg |
| Nominee1: | Brock Adams |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 677,471 |
| Percentage1: | 50.66% |
| Nominee2: | Slade Gorton |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 650,931 |
| Percentage2: | 48.67% |
| Map Size: | 275px |
| U.S. Senator | |
| Before Election: | Slade Gorton |
| Before Party: | Republican Party (United States) |
| After Election: | Brock Adams |
| After Party: | Democratic Party (United States) |
The 1986 United States Senate election in Washington was held on November 3, 1986. Incumbent Republican Senator Slade Gorton lost re-election to former Transportation Secretary Brock Adams. Gorton later won Washington's other Senate seat in 1988 and 1994 before losing re-election again in 2000.