High Quality Content by WIKIPEDIA articles! Lemon Township is one of thirteen townships in Butler County, Ohio, United States. Located in the northeastern part of the county, it includes most of the city of Monroe and now exists as six disconnected pieces because of annexations by Monroe and Middletown. It has a population of 8,607 in 2000, down from 12,172 in 1990 because of annexations by Middletown, and of those 8,607, only 2,335 live in the unincorporated portion of the township. One of these places is the census designated place of South Middletown. It is the only Lemon Township statewide.