| Election Name: | 1990 United States Senate election in Illinois |
| Country: | Illinois |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1984 United States Senate election in Illinois |
| Previous Year: | 1984 |
| Next Election: | 1996 United States Senate election in Illinois |
| Next Year: | 1996 |
| Election Date: | November 6, 1990 |
| Image1: | Sen. Paul Simon.jpg |
| Nominee1: | Paul Simon |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 2,115,377 |
| Percentage1: | 65.07% |
| Nominee2: | Lynn Morley Martin |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 1,135,628 |
| Percentage2: | 34.93% |
| U.S. Senator | |
| Before Election: | Paul Simon |
| Before Party: | Democratic Party (United States) |
| After Election: | Paul Simon |
| After Party: | Democratic Party (United States) |
| Turnout: | 53.90% |
The 1990 United States Senate election in Illinois was held on November 6, 1990. Incumbent Democratic U.S. Senator Paul Simon sought re-election to a second term in office. Simon was opposed by Republican nominee Lynn Morley Martin, a U.S. Congresswoman from Illinois's 16th congressional district, whom he easily defeated to win a second and final term in the Senate.
Primaries were held March 20, 1990.
The primaries and general elections coincided with those for House, as well as those for state offices.
For the primaries, turnout was 23.02%, with 1,384,324 votes cast.[1] For the general election, turnout was 53.90%, with 3,251,005 votes cast.[2]
At the start of the election, Martin was considered a formidable challenger, but her campaign floundered – in ads, Martin poked fun at Simon's signature bow tie, but the ad campaign, an attempt at humor, was seen by some as petty and mean-spirited. Martin's campaign suffered from poor fundraising as well, being outspent by Simon by a margin of two-to-one. Simon's popularity proved too much to overcome, and he won with 65 percent of the vote, carrying all but two counties in the state; Edwards County in the southeast and McHenry County outside Chicago, in the heart of the district Martin represented for most of the 1980s. In a midterm favorable to Democrats, Martin was further hurt by negative campaign tactics deployed by advisor Roger Ailes, as well as a number of gaffes. Including, referencing downstate voters as "rednecks".[3] Martin raised the most campaign funds out of any Republican Senate challenger that cycle.[3]