The 85th district is a multi-county district established in 1966 that now comprises Champaign County and portions of Logan County including Bellefontaine, De Graff, Huntsville, Lakeview, Quincy, Russells Point, Valley Hi and Zanesfield and portions of Shelby County including Lockington, Port Jefferson and Sidney.
It makes up one-third of the 12th Senate District.