Chironomidae (Diptera) were collected from Cedar Bog, Champaign County, OH. Cedar Bog is an alkaline fen formed by numerous springs that collect to form Cedar Run. An attempt was made to collect all life history stages and to rear late instar larvae and pupae under laboratory conditions. Ninety-six taxa were collected from the fen. Twelve taxa were recognized as new species. Taxa for which this study represent a significant range extension are: Bethbilbeckiafloridensis Fittkau & Murray, Paramerina smithae (Sublette), Radotanypus florens (Johannsen) n. comb., Odontomesa ferringtoni Saether, and Rheocricotopus (s.s.) effusoides Saether.