Dalhousie Township was opened for settlement in 1820, then part of Carleton County. From 1824 to 1845, Dalhousie Township was part of Lanark County, in Bathurst District. From January 1, 1850 to August 1866, Dalhousie Township was part of the United Counties of Lanark and Renfrew. From 1866 to 1883 the Townships of Lavant, Dalhousie and North Sherbrooke were joined for administrative purposes.
In 1883, the Township of Lavant separated from Dalhousie and North Sherbrooke. In 1975, the Township of Lavant amalgamated with Dalhousie and North Sherbrooke for administrative purposes.
In 1997, Lavant, Dalhousie and North Sherbrooke Township amalgamated with Lanark Township and Lanark Village to form the municipality of North West Lanark. On July 1, 1997 the municipality of North West Lanark amalgamated with Darling Township to form the Township of Lanark Highlands.