Ishim is a town in the south of Tyumen Oblast, Russia. It was founded in 1670 as the village of Korkina Sloboda.
In 1721, by the order of Tsar Peter the Great the village gained the right to establish Nikolskaya Trade Fair which rapidly became one of the most important trade fairs in Siberia. This trade fair took place twice a year on the Saint Nicholas day until 1919. In 1782, by the order of Empress Catherine the Great, Korkina Sloboda was renamed Ishim and was granted town status.
In 1918, Ishim became the administrative center of Ishimsky Uyezd. In 1984, the city began a sister city relationship with Grand Forks, North Dakota in the United States. This relationship terminated in the late 1990s due to economic turmoil in Ishim.