The 9th Wisconsin Infantry Regiment was a volunteer infantry regiment that served in the Union Army during the American Civil War.

It consisted predominantly of recent immigrants from German-speaking countries.

It participated in an expedition into Indian Territory (present-day Oklahoma) in summer 1862.

The 9th Wisconsin's commander and most of the regiment's personnel mustered out on December 3, 1864, upon expiration of their term of service.

[2] The regiment lost 77 enlisted men killed in action or who later died of their wounds, plus another 114 enlisted men who died of disease, for a total of 191 fatalities.