| Election Name: | 1986 United States Senate election in Illinois |
| Country: | Illinois |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1980 United States Senate election in Illinois |
| Previous Year: | 1980 |
| Next Election: | 1992 United States Senate election in Illinois |
| Next Year: | 1992 |
| Election Date: | November 4, 1986 |
| Image1: | Alan Dixon (Illinois Blue Book Portrait 1989-1990).jpg |
| Nominee1: | Alan Dixon |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 2,033,783 |
| Percentage1: | 65.13% |
| Nominee2: | Judy Koehler |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 1,053,734 |
| Percentage2: | 33.74% |
| U.S. Senator | |
| Before Election: | Alan J. Dixon |
| Before Party: | Democratic Party (United States) |
| After Election: | Alan J. Dixon |
| After Party: | Democratic Party (United States) |
| Turnout: | 52.01% |
The 1986 United States Senate election in Illinois was held on November 4, 1986. The incumbent Democrat U.S. Senator Alan J. Dixon won re-election to a second term. Until 2022, this was the most recent election in which an incumbent Senator won re-election to Illinois' Class 3 seat and was elected to more than one full term.
Primaries were held March 18, 1986.
The primaries and general elections coincided with those for House, as well as those for state offices.
For the primaries, turnout was 21.84%, with 1,333,989 votes were cast.[1]
For the general election, turnout was 52.01%, with 3,122,833 votes cast.[2]
Dixon easily won the senate race. Koehler fared poorly throughout most parts of the state, only winning 10 of the state's 102 counties.[2]
Koehler's campaign was regarded as underfinanced.[5]