The 42nd Wisconsin Infantry Regiment was a volunteer infantry regiment that served in the Union Army during the American Civil War.

The 42nd Wisconsin was organized at Milwaukee, Wisconsin, and mustered into Federal service on September 7, 1864.

The regiment was mustered out on June 20, 1865.

The 42nd Wisconsin suffered 58 enlisted men who died of disease, for a total of 58 fatalities.

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