A person appointed or elected to act for another, especially a person sent with a special commission to act in the place of another; a lieutenant; a viceroy. A prince sends a deputy to a diet or council, to represent him and his dominions. A sheriff appoints a deputy to execute the duties of his office. The towns in New England send deputies to the legislature. In the latter sense, a deputy has general powers, and it is more common to use the word representative.

In law, one that exercises an office in anothers right, and the forfeiture or misdemeanor of such deputy shall cause the person he represents to lose his office.