The name Towamencin is of Native American origin, although there exists some disagreement about the name's history. Some early sources, such as the 1850 United States Census, record the township's name as "Towamensing." The Towamensing name appears on local tax records as late as 1922, although the 1920 census records the township with the modern spelling of Towamencin. According to "History of Montgomery County, Pennsylvania, Volume II", both the Towamensing and Towamencin spellings were in use circa 1884. The same source cites Towamensing as the original spelling, but notes that the Towamencin spelling was in use for government records in Norristown. It is unclear when the modern spelling of Towamencin was universally adopted.