Lanark Highlands is a township in eastern Ontario, Canada in Lanark County. The township administrative offices are located in the village of Lanark.
On May 15, 1997, the United Township of Lavant, Dalhousie and North Sherbrooke was amalgamated with the Township of Lanark and the Village of Lanark to form the Township of North West Lanark. In turn, North West Lanark was merged with Darling Township on July 1, 1997, to create the Township of Lanark Highlands.
The township comprises the communities of:
In the 2021 Census of Population conducted by Statistics Canada, Lanark Highlands had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021.