The name "Muncaster" means 'Mula's/Muli's Roman site', which perhaps refers to the Roman fort Glannoventa at Ravenglass.[5] The surname Muncaster[6] derives from the place. It was anciently called "Meolceastre".[7] In 1847 the parish contained the townships of Muncaster and Birkby.[8] On 25 March 1886 part of Millom was transferred to the parish.[9] From 1974 to 2019 it was in the Copeland district.