Ellsworth is a city in and the county seat of Ellsworth County, Kansas, United States. As of the 2010 census, the city population was 3,120.
Once called "The Wickedest Cattletown in Kansas", the city is named for Fort Ellsworth, which was built in 1864. Due to speculation on imminent railroad construction, the population of Ellsworth boomed to over two thousand by the time it was incorporated in 1867. It has since been said, ""Abilene, the first, Dodge City, the last, but Ellsworth the wickedest".
Ellsworth was a bustling cattle town for a time during the late 1860s but its cattle trade had dwindled down by the mid-1880s. During this period it was known for being one of the wildest cattle towns, the scene of numerous killings following shootouts between drunken cowboys, and the town sported numerous saloons, brothels and gambling halls, with prostitution being rampant. Wild Bill Hickok ran for Sheriff there in 1868, but was defeated by former soldier E.W. Kingsbury. Kingsbury was an extremely effective lawman, but had to have the help of the local police to control Ellsworth itself, as he also had the county to deal with. Violence inside Ellsworth was commonplace. Ellsworth Marshal Will Semans was shot and killed on September 26, 1869, while attempting to disarm a rowdy man in a dance hall.