The jurisdiction of a municipal court may extend only to the limits of the city where it is situated, or its jurisdiction may extend to certain areas outside the city or even cover a whole county. Within a given county, wherever the jurisdiction of a municipal court does not extend, the jurisdiction of a county court does, so that all of Ohio is within the jurisdiction of either a municipal or county court. A county may have one county court judge, more than one or none at all if the whole county is within the jurisdiction of a municipal court. The mayor is not required to be trained in the law, but must complete special courses conducted by the Supreme Court of Ohio. The courts of common pleas were the original courts of general jurisdiction of the Ohio judicial system.
Every county has a common pleas court, served by one or more judges.
All civil suits of a serious nature involving real estate, property, divorce, dissolution, tort, and contract and business relationships are tried in this court. Criminal cases involving serious crimes where the penalty may be imprisonment for one year or more are also tried in this court. Common pleas courts also have authority to hear some appeals from county, municipal and mayor's courts within their jurisdiction, and to hear appeals from orders of administrative agencies and officers. A judge of the court of common pleas may be designated domestic relations judge. In some counties, he or she has jurisdiction over divorce, alimony, annulment and custody in family disputes.