Arnold is an unincorporated community in Jerome Township, Union County, Ohio, United States. It is located at 40°08′31″N 83°15′03″W / 40.14194°N 83.25083°WCoordinates: 40°08′31″N 83°15′03″W / 40.14194°N 83.25083°W, along U.S. Route 42, between New California and Plain City.
The Arnold Post office was established on June 21, 1894, but was discontinued on February 28, 1910. The mail service is now sent through the Plain City branch.
- Curry, W.L., History of Jerome Township, Union County, Ohio, Heritage Books, Inc., Columbus, Ohio, 1913