The State constitution provides for a county court in each of the counties of the state, though all such courts do not exercise judicial functions. In the more populous counties, the county judge may devote their full attention to the administration of county government.

The constitutional county courts have original jurisdiction over all criminal cases involving Class A and Class B misdemeanors, which are the more serious minor offenses. These courts usually have appellate jurisdiction in cases appealed from justice of the peace and municipal courts, except in counties where county courts at law have been established.

Because the Constitution limits each county to a single county court, the Legislature has created statutory county courts at law in more populous counties to aid the single county court in its judicial functions.

The legal jurisdiction of the special county-level trial courts varies considerably and is established by the statute which creates the particular court. The jurisdiction of statutorily-created county courts at law may be concurrent with the jurisdiction of the county and district courts in the county.

The civil jurisdiction of most county courts at law varies but is usually more than that of the justice of the peace courts and less than that of the district courts. County courts at law usually have appellate jurisdiction in cases appealed from justice of the peace and municipal courts.