cheltenham township is a home rule township in montgomery county, pennsylvania, united states. cheltenham's population density ranges from over 10,000 per square mile in rowhouses and high-rise apartments along cheltenham avenue to historic neighborhoods in wyncote and elkins park. it is the most densely populated township in montgomery county. the population was 36,793 at the 2010 u.s. census, making it the third most populous township in montgomery county and the 27th most populous municipality in pennsylvania. it was originally part of philadelphia county, and it became part of montgomery county upon that county's creation in 1784.