Hiram Augustus Calvin (April 6, 1841 – January 13, 1932) was a businessman and political figure in Ontario, Canada.
He was born on Garden Island, Canada West, the son of Delino Dexter Calvin and Marion Breck, and was educated there, at the Woodstock Literary Institute and at Queen's University.
Calvin joined his father's business and later succeeded him as lumber merchant, ship builder and forwarder.
He also helped establish the Kingston Foundry and Machinery Company.
Calvin was first elected to the House of Commons in an 1892 by-election held after George Airey Kirkpatrick was named Lieutenant-Governor.