| Election Name: | 1984 Illinois Democratic presidential primary |
| Ongoing: | no |
| Previous Election: | 1980 Illinois Democratic presidential primary |
| Previous Year: | 1980 |
| Next Election: | 1988 Illinois Democratic presidential primary |
| Next Year: | 1988 |
| Type: | presidential |
| Country: | Illinois |
| Candidate1: | Walter Mondale |
| Color1: | 567953 |
| Home State1: | Minnesota |
| Popular Vote1: | 670,951 |
| Percentage1: | 40.43% |
| Candidate2: | Gary Hart |
| Color2: | a59400 |
| Home State2: | Colorado |
| Popular Vote2: | 584,579 |
| Percentage2: | 35.23% |
| Candidate3: | Jesse Jackson |
| Color3: | 73638c |
| Home State3: | Illinois |
| Popular Vote3: | 348,843 |
| Percentage3: | 21.02% |
| Map Size: | 280px |
The 1984 Illinois Democratic presidential primary was held on March 20, 1984, in the U.S. state of Illinois as one of the Democratic Party's statewide nomination contests ahead of the 1984 presidential election.
Jackson's voters were 88% black, 10% white, and 1% were members of other groups.
Former Vice President Walter Mondale won the contest by over 40% of the popular votes.
| Candidate | Votes | % | Delegates | |
|---|---|---|---|---|
| Walter F. Mondale | 670,951 | 40.43 | ||
| Gary Hart | 584,579 | 35.23 | ||
| Jesse L. Jackson | 348,843 | 21.02 | ||
| 25,336 | 1.53 | |||
| 19,800 | 1.19 | |||
| Betty Jean Williams | 4,797 | 0.29 | ||
| 2,786 | 0.17 | |||
| 2,182 | 0.13 | |||
| Write-in | 151 | 0.01 | ||
| Total | 1,659,425 | 100 |