Lanark is an unincorporated community and former village in the municipality of Lanark Highlands, Lanark County, in Eastern Ontario, Canada. The village was first settled in 1820 by Scottish immigrants who named it after the town of Lanark in Scotland. In 1823 it established its first post office. It soon became a major hub of the lumbering and textile i…Lanark is an unincorporated community and former village in the municipality of Lanark Highlands, Lanark County, in Eastern Ontario, Canada. The village was first settled in 1820 by Scottish immigrants who named it after the town of Lanark in Scotland. In 1823 it established its first post office. It soon became a major hub of the lumbering and textile industries, both of which used the Clyde River which runs through the village, as a source of power and as a transportation route to transport logs east to the Ottawa River.