The 73rd Regiment Illinois Volunteer Infantry, known as the "Persimmon Regiment" or the "Preacher's Regiment" was an infantry regiment that served in the Union Army during the American Civil War.

73rd Regiment Illinois was organized at Camp Butler, Illinois and mustered into Federal service on August 21, 1862.

The regiment was discharged from service on June 10, 1865.

The regiment suffered 5 officers and 109 enlisted men who were killed in action or mortally wounded and 167 enlisted men who died of disease, for a total of 281 fatalities.

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