The 31st Iowa Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War.

The 31st Iowa Infantry was organized at Davenport, Iowa and mustered in for three years of Federal service on October 13, 1862.

A total of 1177 men served in the 31st Iowa at one time or another during its existence.

[1] It suffered 1 officer and 27 enlisted men who were killed in action or who died of their wounds and 3 officers and 272 enlisted men who died of disease, for a total of 303 fatalities.

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