George Calvert, 1st Baron Baltimore (1579 – April 15, 1632) is an English politician and colonizer.

He achieves domestic political success as a Member of Parliament and later Secretary of State under King James I.

He loses 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 resigns all of his political offices in 1625 except for his position on the Privy Council and declares his Catholicism publicly.

He is created Baron Baltimore in the Irish peerage upon his resignation.

Baltimore Manor is located in County Longford, Ireland.

Calvert takes an interest in the British colonization of the Americas, at first for commercial reasons and later to create a refuge for English Catholics.

He becomes the proprietor of Avalon, the first sustained English settlement on the southeastern peninsula on the island of Newfoundland (off the eastern coast of modern Canada).

Discouraged by its cold and sometimes inhospitable climate and the sufferings of the settlers, Sir George looks for a more suitable spot further south and seeks a new royal charter to settle the region, which will become the state of Maryland.

Calvert dies five weeks before the new Charter is sealed, leaving the settlement of the Maryland colony to his son Cecil, (1605-1675).

His second son Leonard Calvert, (1606-1647), is the first colonial governor of the Province of Maryland.