| Election Name: | 1920 Illinois gubernatorial election |
| Country: | Illinois |
| Flag Year: | 1915 |
| Type: | Presidential |
| Ongoing: | no |
| Previous Election: | 1916 Illinois gubernatorial election |
| Previous Year: | 1916 |
| Next Election: | 1924 Illinois gubernatorial election |
| Next Year: | 1924 |
| Election Date: | November 2, 1920 |
| Image1: | File:Len Small (3x4).jpg |
| Nominee1: | Len Small |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 1,243,148 |
| Percentage1: | 58.87% |
| Nominee2: | James Hamilton Lewis |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 731,541 |
| Percentage2: | 34.64% |
| Map Size: | 300px |
| Governor | |
| Before Election: | Frank Orren Lowden |
| Before Party: | Republican Party (United States) |
| After Election: | Len Small |
| After Party: | Republican Party (United States) |
The 1920 Illinois gubernatorial election was held on November 2, 1920.
Incumbent first-term Republican Governor Frank Orren Lowden declined to stand for re-election. He was an unsuccessful candidate for the Republican nomination for U.S. President at the 1920 Republican National Convention.
Republican nominee Len Small defeated Democratic nominee James Hamilton Lewis with 58.78% of the vote.
Primary elections were held on September 15, 1920.