The 26th Wisconsin Infantry Regiment was a volunteer infantry regiment that served in the Union Army during the American Civil War.

The regiment had a total enrollment of 1,089 men during its service, of which 191, (17.5%) were killed in action or mortally wounded, the fourth-highest percentage of any Union regiment.

Except for Company G, which consisted in part of native born Americans, the regiment was composed almost entirely of men of German birth or German parentage.

Moved from Washington, D.C., to Fairfax Courthouse, Virginia, October 15, 1862.

Battle of Fredericksburg, Virginia, December 15 (Reserve).

Pursuit of Robert E. Lee's army to Manassas Gap, Virginia, July 5–24.

Duty in Lookout Valley till November 22.

Duty in Lookout Valley till January 25, 1864, and at Whiteside, Alabama, until April 23.

Demonstration at and Battle of Rocky Face Ridge May 8–11.

Operations on line of Pumpkin Vine Creek and battles about Dallas, New Hope Church and Allatoona Hills May 25-June 5.

Taylor's Hole Creek, Averysboro, North Carolina, March 16.

March to Washington, D. C., via Richmond, Virginia, April 29-May 17.

[4] The 26th Wisconsin suffered 12 officers and 176 enlisted men killed in action or who later died of their wounds, plus another 77 enlisted men who died of disease, for a total of 265 fatalities.

[5] A soldier from the 26th – a nervous lad – is featured in a scene in the third chapter of MacKinlay Kantor's Pulitzer Prize-winning novel Andersonville (1955).