Tōon is a city located in Ehime Prefecture, Japan. As of 1 September 2022, the city had an estimated population of 33,276 in 15571 households and a population density of 160 persons per km2. The total area of the city is 211.30 square kilometres (81.58 sq mi). The city name may be romanized as 'Toon', 'Tôon', 'Tōon' or 'Tohon'.

Ehime Prefecture is a prefecture of Japan located on the island of Shikoku. Ehime Prefecture has a population of 1,334,841 and has a geographic area of 5,676 km2. Ehime Prefecture borders Kagawa Prefecture to the northeast, Tokushima Prefecture to the east, and Kōchi Prefecture to the southeast.