The Mount Vernon school board fired John Freshwater last month, following a state hearing officer's recommendation.
Freshwater was accused of preaching Christian beliefs in class and of using a scientific device to mark students with a cross. The hearing officer said there was a plausible explanation for that but didn't explain further.
The Columbus Dispatch reports the appeal alleges the officer's report was biased and that parts of Freshwater's case violated his legal rights. The appeal says new information has become available since the hearing and Freshwater could present more evidence contradicting the report.
Messages left late Friday for the Mount Vernon school district and Freshwater's lawyer were not immediately returned.
Information from: The Columbus Dispatch, http://www.dispatch.com