Semley is a village and former civil parish, now in the parish of Sedgehill and Semley, in Wiltshire, England, about 3 miles (4.8 km) north-east of Shaftesbury in neighbouring Dorset. The hamlet of Sem Hill lies about a quarter of a mile west of the village. In 1961 the parish had a population of 477.

Cecil Calvert, 2nd Baron Baltimore was an English politician, peer and lawyer who was the first proprietor of Maryland. Born in Kent in 1605, he inherited the proprietorship after the death of his father, George Calvert, 1st Baron Baltimore, for whom it had been intended. Calvert proceeded to establish and manage the Province of Maryland as a proprietary colony for English Catholics from his English country house of Kiplin Hall in North Yorkshire.