From 1873 – 1878, Metcalfe was Alderman for Frontenac Ward in Kingston. In 1879, he became a member of the Provincial Parliament of Ontario. After the death of Sir John A. Macdonald in 1891, he succeeded him as member for Kingston in the Federal parliament. Metcalfe was Warden of Kingston Penitentiary from May 22nd 1896 to May 17th 1899.
It was said of Metcalfe that he had “the suavity of a Laurier, the magnetic personality of a Macdonald, the volubility of a Tupper and the rhetoric of Cartwright…”.(Weekly British Whig, Jan. 5, 1925). He died in Kingston on January 1, 1925, predeceased by his wife and five of his eleven children.