Cecilius Calvert, 2nd Baron Baltimore, 1st Proprietor Governor of Maryland, 9th Proprietor Governor of Newfoundland (August 8, 1605 – November 30, 1675), usually called Cecil, was an English coloniser who was the first proprietor of the Maryland colony. He received the proprietorship that was intended for his father, George Calvert, the 1st Lord Baltimore, who died shortly before it was granted. Cecil established Maryland from his home in England, and as a Roman Catholic continued the legacy of his father by promoting religious tolerance in the colony.
Forming it based on the ideas of freedom of religion and separation of church and state, Maryland became known as a haven for Roman Catholics in the New World. Cecil governed Maryland for forty-two years. He also served as Governor of Newfoundland.