The current court is the successor to courts pre-dating the County Courts Act 1846, which introduced the modern system of county courts. The 1846 Act deliberately did not extend to the City of London, where the prior constituted courts continued to exercise jurisdiction:
|City of London Court||Known as the "Sheriff's Court" until 1852, before becoming the "City of London Small Debts Court". Under the County Courts Act 1867, it became known as the "City of London Court".||Until the passage of the Local Government Act 1888, its judge was elected by the Corporation of the City of London. It had all the jurisdiction of a county court, but persons who merely had employment in the City were also subject to its jurisdiction. It had exclusive jurisdiction over cases of replevin.|
|Mayor's Court||A court of great antiquity, having the status of an inferior court of record.||Unlimited jurisdiction in contract, tort and ejectment, where the whole cause of action arose in the City; and jurisdiction up to £50 where part of the cause of action arose in the City, or where the defendant dwelt or carried on business there either then or within the previous six months.|
The two courts were combined with effect from 1 January 1921 by the Mayor's and City of London Court Act 1920.High Court procedure was declared to apply to matters formerly dealt with by the Mayor's Court, while county court procedure applied to matters falling under the City of London Court.
Under s. 42 of the Courts Act 1971, the old Mayor's and City of London Court was abolished, the City of London was made a county court district, and the new county court for the city of London was given the name of its predecessor. It was the only county court not to contain "county" in its title. The individual county courts have since been replaced by a single County Court for England and Wales.