Gerald Ephraim Hart was born on March 26, 1849, in Montreal, Quebec.

He was an insurance agent, numismatist, and author. He came from a prominent Canadian Jewish family. He was educated in Trois-Rivières, Montreal, and New York. He made his career in the insurance business and was based in Montreal from 1869 until 1896. He became general manager of the Citizens Insurance Company and then from 1890 held a similar position in the Montreal office of the Phoenix Fire Company of Hartford, Connecticut. Around 1896 he moved to Florida where he lived until 1934 when he returned to Montreal. Hart was best known as a collector of coins, medals, books, stamps, china, and furniture. His collections were closely linked to his interest in Canadian history. He published two books in this field, "The Fall of New France, 1755-1760" (1888) and "The Quebec Act, 1774" (1891). He was a life member of the Numismatic and Antiquarian Society of Montreal and from as early as 1869 served as an officer of the Society, publishing regularly in its journal.

He died on July 13, 1936, in Montreal, Quebec.