Hiram Emerson McCallum (August 14, 1899 – January 13, 1989) was a mayor of Toronto, Ontario, from 1948 to 1951.

Born in 1899 at Caledon East, Ontario,[1] his first job was at The Mail and Empire newspaper as a clerk in the advertising department.

From that start, he moved up (in 1946) to vice-chairperson of the city of Toronto's board of control.

As mayor he started Toronto's Yonge Street line and worked towards a regional government.

With his wife Margaret he had a daughter Dorothy and a son Bruce, and he was the grandfather of four children.