Thomas Stewart Traill

Dr. Thomas Stewart Traill (October 29 1781- July 30 1862) was a Orcadian professor of medical jurisprudence at the University of Edinburgh.

Traill was born at Kirkwall in the Orkney Islands, and studied at Edinburgh University. He practiced medicine for 30 years in Liverpool, and was a founder of the Royal Institution, the Liverpool Mechanics' Institution and the Literary and Philosophical Society of Liverpool. He became acquainted with the Arctic explorer William Scoresby, contributing a list of animals observed in eastern Greenland to Scoresby's Journal of a Voyage to the Northern Whale Fishery (1823). Scoresby named Traill Island in Greenland for him.

When John James Audubon arrived in Liverpool in July 1826 Traill helped him to find a publisher for his The Birds of America. Audubon named the Traill's Flycatcher after him, which at one time referred to a species which included both the Willow Flycatcher (Empidonax traillii) and the Alder Flycatcher (Empidonax alnorum).

Traill returned to Edinburgh University in 1833 as a professor of medical jurisprudence. He edited the 8th edition of the Encyclopædia Britannica (1852-61), which concluded a year before his death.