Court records include record books, dockets, bonds, journals, petitions, minutes, final records, case files, and so forth. They contain many primary source materials that are useful for genealogical research. The Family History Library has many Ohio court records. Additional records are available at county courthouses, the Ohio Historical Society, and the National Archives—Great Lakes Region. Major courts that kept records of genealogical value were established as follows:

1787-pres.	Courts of common pleas have districtwide jurisdiction over felonies, marriages, major civil cases, juvenile matters, probates until 1852, naturalizations until 1860 and after 1906, chancery matters until 1900, and divorces until 1894. The Family History Library has copies of some of the common pleas records, such as Cuyahoga County journals for 1823 to 1852.
1787-pres.	Supreme Court is a statewide appellate court. It originally had jurisdiction over common law and chancery matters.
1787-1802, 1852-pres.	Probate court has handled guardianship, general probate, land sales, a few divorces, and naturalizations.
1800s-pres.	County, municipal, mayor, justice of the peace, and police courts have kept records with some genealogical value.
1851-1883	District courts have countywide jurisdiction over civil and criminal cases, including chancery and divorces. The Family History Library has some district court records, such as Lake County records for 1845 to 1884.
1883-1912	Circuit courts have countywide jurisdiction over civil and criminal records, including equity and divorce. They have been replaced by courts of appeal. The Family History Library has some circuit court records.