| 143rd Regiment Illinois Volunteer Infantry | |
|---|---|
 Illinois state flag | |
| Active | June 11, 1864, to September 26, 1864 |
| Country | United States |
| Allegiance | Union |
| Branch | Infantry |
The 143rd Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War. It was among scores of regiments that were raised in the summer of 1864 as Hundred Days Men, an effort to augment existing manpower for an all-out push to end the war within 100 days.