The 48th Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.

The 48th Illinois Infantry was organized at Camp Butler, Illinois and mustered into Federal service in September, 1861.

The regiment was mustered out on August 15, 1865.

The regiment suffered 10 officers and 113 enlisted men who were killed in action or mortally wounded and 6 officers and 251 enlisted men who died of disease, for a total of 380 fatalities.

This article about a specific military unit of the American Civil War is a stub.