It lies midway between Cross Fell to the north and the town of Appleby-in-Westmorland to the south.

The place-name 'Knock' is first attested in a Yorkshire charter from between 1150 and 1162, where it appears as Chonoc-salchild.

The name means 'hillock', from the Brittonic *cnuc,[3] Old Irish cnocc or Irish cnoc; an apparent reference to the nearby Knock Pike, which is 1,306 feet high,[4] and can be seen in the photo to the right.

Circa 1870, it had a population of 197 as recorded in the Imperial Gazetteer of England and Wales.

The former chapel in Knock was gutted in a fatal fire in April 2018 that killed two people.