Granny Boswell (c. 1817–1909) had a reputation as a witch in early 20th-century Helston, Cornwall, UK.
Of Romany lineage, she was born in Ireland and later married Ephraim Boswell, known as the 'King of the Gypsies'. From the 1860s onwards she lived in west Cornwall, mostly on the Lizard, and ended her days a pauper at the Helston workhouse. In his Seven Cornish Witches (1998), Kelvin Jones made much of her as a white witch or healer without giving any evidence for it.[according to whom?] Contemporary sources state that Boswell was regarded as a nuisance by the local authorities and feared by many people in Helston as an ill-wisher.
Her spirit is said to haunt the old Mevagissey Wash House in Meadow Street.