He was mainly educated in the south of France; from boyhood he collected mollusc shells, and was greatly influenced by a French work on molluscan anatomy.

In July he became honorary secretary of the Royal Society of Queensland, and in 1890, at the invitation of the administrator, Sir William Macgregor, he visited New Guinea, did some exploring, and made important collections.

In April 1891 he joined the Australian Museum staff as assistant in charge of land shells, and about five years later was appointed conchologist.

[2] Hedley collaborated with Professor William A. Haswell and Sir Joseph Verco in investigating the continental shelf and co-operated with the Commonwealth Advisory Council of Science and Industry.

[5] Hedley was a keen explorer and visited most of the coast of eastern Australia, and the Gulf of Carpentaria, New Guinea, New Caledonia, and the Ellice Group.

He had become assistant curator of the Australian museum in 1908 and in 1920 he succeeded Robert Etheridge, Junior as principal keeper of collections.

He was awarded the David Syme prize in 1916, and in 1925 received the Clarke Medal from the Royal Society of New South Wales.

His work, and especially in regard to the zoo-geographical history of the Pacific Ocean, gave him a high place among Australian zoologists.