Oldtown was founded on the site of a former Shawnee settlement. White settlers first called the place Old Chillicothe, and under the latter name was it platted in 1839. A post office called Old Town was established in 1886, and remained in operation until 1902.
- U.S. Geological Survey Geographic Names Information System: Oldtown, Ohio
- Robinson, G.F. History of Greene County, Ohio. Chicago: S.J. Clarke Publishing Company. p. 177. ISBN 978-5-87776-001-1.
- Dills, R. S. (1881). History of Greene County: Together with Historic Notes on the Northwest, and the State of Ohio ... Odell & Mayer. p. 436.
- "Greene County". Jim Forte Postal History. Retrieved 13 January 2016.