George Calvert, 1st Baron Baltimore (1579 – 15 April 1631) was an English politician and colonizer. He achieved domestic political success as a Member of Parliament and later Secretary of State under King James I. He lost much of his political power after his support for a failed marriage alliance between Prince Charles and the Spanish House of Habsburg royal family. Rather than continue in politics, he resigned all of his political offices in 1625 except for his position on the Privy Council and declared his Catholicism publicly. He was created Baron Baltimore in the Irish peerage upon his resignation. Baltimore Manor was located in County Longford, Ireland.