Crutherland Linn is a waterfall on the Rotten Calder Water (also known as Calder Water) in South Lanarkshire, Scotland. It is also referred to as Flatt Linn, the two names appearing to describe the same feature on the river.

The Rotten Calder is noted for its many waterfalls set within a steep, romantically scenic gorge that was celebrated in 18th and 19th century literature for its grandeur and lush, ivy-clad crags.

Crutherland Linn is one of several named falls on the river, alongside Torrance Linn, Black Linn, Trough Linn, and Calderwood Linn, among others.