Fairmont City is organized under Illinois law as a "Village". In this form of local government, the President or Mayor, and six Trustees are elected from the village at large, and form the legislative body. The village also has an elected Village Clerk.
Appointments to all non elected offices are made by the Mayor, with the advise and consent of the Board of Trustees.
The Village Board of Trustees meet twice per month on the first and third Wednesday of the month at 7:00 P.M. The meetings are held at the Fairmont City Community Center, located at 4001 Cookson Road in Fairmont City. The Community Center is handicapped accessible.