As of the United States 2010 Census, the township population was 22,254, which represents growth of 27% since 2000 and more than 130% since the 1990 Census population figure of 9,612.
As of the United States 2000 Census, the township population was 17,481. The Census Bureau's 2008 population estimate for Montgomery Township was 22,958, which represents growth of 31% since 2000 and almost 140% since the 1990 Census population figure of 9,612.