What is now Rusk County was created by the Wisconsin legislature in 1901 from the northern part of Chippewa County. The new county was named Gates County after a Milwaukee land speculator, but in 1905 the county was renamed for Jeremiah McLain Rusk who had served as the governor of Wisconsin from 1882 to 1889 and was U. S. Secretary of Agriculture under President Benjamin Harrison from 1889 to 1893.
The only incorporated city in Rusk County is Ladysmith, which is the county seat. Ladysmith was founded in 1885 and is located where the Soo Line railroad crossed the Flambeau River. The settlement was originally called Flambeau Falls, then Corbett, then in 1891 it was renamed Warner. Finally in 1901 it was renamed Ladysmith, supposedly after the bride of Charles Smith was the head of the Menasha Wooden Ware Company.
The Rusk County courthouse is located at 311 Miner Avenue East in Ladysmith.