The Findlay Police Department says 30 gravestones at Maple Grove Cemetery were damaged.
The vandalism occurred overnight from Tuesday into Wednesday in the northeast section of the cemetery.
Many of the damaged gravestones date back to the 1800s.
Anyone with information about the vandalism is urged to contact the Findlay Police Department at 419-424-7150 or Crime Stoppers at 419-425-8477.
People who submit tips may be eligible for reward money.