Rannerdale Knotts is a fell in the Lake District of Cumbria, England. Rising from the Buttermere valley, it is one of the smaller Cumbrian hills and is overlooked by a number of surrounding fells, such as Grasmoor, Whiteless Pike and, across Crummock Water, Mellbreak and the High Stile ridge. Rannerdale Knotts is said to be the site of a battle between the native Cumbrians and Norsemen and the invading Normans in the late 11th or early 12th century.