Watermillock is a village and former civil parish, now in the parish of Matterdale, in the Westmorland and Furness district, in the ceremonial county of Cumbria, England. It is on the western shore of Ullswater, in the English Lake District. In 1931 the civil parish had a population of 448. On 1 April 1934 the civil parish was merged into Matterdale.