Lanark is a town in Portage County, Wisconsin, United States.

As of the census[2] of 2000, there were 1,449 people, 546 households, and 423 families residing in the town.

There were 659 housing units at an average density of 18.4 per square mile (7.1/km2).

18.1% of all households were made up of individuals, and 5.5% had someone living alone who was 65 years of age or older.

Out of the total population, 9.8% of those under the age of 18 and 5.8% of those 65 and older were living below the poverty line.