Benedict Swingate Calvert was a planter, politician and a Loyalist in Maryland during the American Revolution. He was the son of Charles Calvert, 5th Baron Baltimore, the third Proprietor Governor of Maryland (1699–1751). His mother's identity is not known, though one source speculates that she was Melusina von der Schulenburg, Countess of Walsingham. As he was illegitimate, he was not able to inherit his father's title or estates, which passed instead to his half brother Frederick Calvert, 6th Baron Baltimore (1731–1771). Benedict Calvert spent most of his life as a politician, judge and planter in Maryland, though Frederick, by contrast, never visited the colony. Calvert became wealthy through proprietarial patronage and became an important colonial official, but he would lose his offices and his political power, though not his land and wealth, during the American Revolution.

Captain Charles Calvert was the 14th Proprietary Governor of Maryland in 1720, at a time when the Calvert family had recently regained control of their proprietary colony. He was appointed governor by his cousin Charles Calvert, 5th Baron Baltimore, who in 1721 came into his inheritance. Calvert worked to reassert the Proprietary interest against the privileges of the colonists as set out in the Maryland Charter, and to ease tensions between the Lords Baltimore and their subjects. Religious tension, which had been a source of great division in the colony, was much reduced under his governorship. Captain Calvert was replaced as governor in 1727 by his cousin Benedict Leonard Calvert, though he continued to occupy other colonial offices. He suffered from early senility and died in 1734.