Charles K. Erwin (December 15, 1837 – January 7, 1905) was an American businessman and politician.
Born in Washington, Lycoming County, Pennsylvania, Erwin settled in Portage, Wisconsin in 1853.
During the American Civil War, Erwin served in the 45th Illinois Volunteer Infantry Regiment.
From 1882 to 1889, Erwin served in the Wisconsin State Senate and was a Republican.
Erwin died suddenly in Savanna, Illinois just as he was about get on a train for a trip to Omaha, Nebraska.