Chris Madsen (1851–1944) was a lawman of the Old West who is best known as being one of The Three Guardsmen, the name given to Madsen and two other Deputy US Marshals who were responsible for the apprehension and/or killing of several outlaws of that era. The Three Guardsmen consisted of Madsen, Bill Tilghman, and Heck Thomas.

Madsen was born in Denmark. He later claimed to have been a soldier in the Danish Army and the French Foreign Legion. He immigrated to the United States in 1876. He was quartermaster sergeant of the Fifth Cavalry and fought in many major Indian campaigns. Later, in 1883, he became President Chester A. Arthur's guide to Yellowstone. By 1885 he had joined the US Marshals as a Deputy Marshal, serving under Judge Isaac Parker out of Fort Smith, Arkansas, with the priority of policing the vast Oklahoma Territory. Over 300 outlaws were either apprehended or killed by Madsen, Thomas and Tilghman, thus leading to their nickname, The Three Guardsmen. They were largely responsible for bringing down outlaw Bill Doolin and his Wild Bunch gang. Madsen was personally responsible for the killings of Doolin gang members Dan "Dynamite Dick" Clifton and "Little Dick" West. Madsen retired in 1905 at the age of 54.