| Unit Name: | 20th Regiment Illinois Volunteer Infantry |
| Dates: | June 13, 1861, to July 16, 1865 |
| Country: | United States |
| Allegiance: | Union |
| Branch: | Infantry |
| Battles: | Fort Henry Battle of Shiloh Battle of Port Gibson Battle of Champion Hill Battle of Big Black River Siege of Vicksburg Battle of Kennesaw Mountain Battle of Atlanta Battle of Jonesboro March to the Sea Battle of Bentonville |
The 20th Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.
The 20th Illinois Infantry was organized at Joliet, Illinois and mustered into Federal service on June 13, 1861, for a three-year enlistment.
The regiment was mustered out of service on July 16, 1865.
The regiment suffered 7 officers and 132 enlisted men who were killed in action or who died of their wounds and 1 officer and 191 enlisted men who died of disease, for a total of 331 fatalities.[1]