Carleton County was created in 1800 from portions of Dundas and Grenville counties. It was named after Guy Carleton, 1st Baron Dorchester. Early Carleton County included a vague area of Eastern Ontario that included most of what is now Lanark County plus the area of what is now Ottawa west of the Rideau River. Originally part of Johnstown District for administrative purposes, it became part of Bathurst District, with judicial seat at Perth in 1823. In 1838, a separate Dalhousie District, with judicial seat at Bytown, was created with the same boundaries as Carleton County had in 1969 when it was abolished. In 1850, the Districts in Ontario were re-distributed into Counties by the Municipal Corporations Act and the administrative district of Dalhousie was replaced by Carleton County.
Also in 1850, all of the townships of Carleton County were incorporated. (see list below) Bytown was incorporated as a town, and Richmond became a village. In 1855 Bytown was renamed Ottawa and became a city. In 1867 New Edinburgh was incorporated as a village and 20 years later was annexed by Ottawa. In 1888 Ottawa East was incorporated as a village and would later be annexed by Ottawa. In 1893 Hintonburg was incorporated as a village. It would be annexed 14 years later by Ottawa. In 1898 Metcalfe was incorporated as a police village. In 1903 Manotick was incorporated as a police village. Rideauview, Westboro and North Gower were incorporated as police villages in 1905. Rideauview was annexed by Ottawa two years later, and Westboro was annexed in 1949. In 1908 Rockcliffe Park was incorporated as a police village, while Janeville was incorporated as a village. Janeville would be incorporated as a town in 1913 as the Town of Eastview, while Rockliffe Park became a full village in 1925. In 1910 Kenmore and Osgoode Station were incorporated as police villages. Ottawa West was incorporated as a police village in 1912 and would be annexed by Ottawa in 1949. In 1922 Overbrook and St. Joseph d'Orleans were incorporated as police villages. In 1950 Overbrook was annexed by Ottawa. In 1939 Hampton Park was incorporated as a police village. It would be annexed by Ottawa ten years later. In 1955 City View was incorporated as a police village. In 1956 Stittsville was incorporated as a police village. Five years later Stittsville became a full village.
In 1963 Eastview (now Vanier) became a city.
Carleton County and today's city of Ottawa have the same borders; except that when Ottawa-Carleton came into existence, it added the Township of Cumberland from Russell County.
Carleton County consisted of the following townships:
Source: Province of Ontario -- A History 1615 to 1927 by Jesse Edgar Middletwon & Fred Landon, copyright 1927, Dominion Publishing Company, Toronto