The city first attained a population of over 5,000 when in 1970, Bellbrook annexed a large part of western Sugarcreek Township. This led to official city status in 1974 and the largest percentage increase in population in the state from 1970 to 1980 (308%).

With the completion of a County sanitary sewer system and under the City's more comprehensive development controls, Bellbrook began growing again in 1979. Over 1000 new housing units have been built since that time and the 26% increase in population between the 1980 and 1990 census was the highest in the Miami Valley. As of the 2000 census, Bellbrook's current population is 7,009.