James Cowan Greenway (7 April 1903 – 10 June 1989) was an American ornithologist. An eccentric, shy and sometimes reclusive man, his survey of extinct and vanishing birds provided the base for much subsequent work on bird conservation.
Greenway was born in New York City, though grew up on the family estate at Greenwich, Connecticut as the son of a wealthy physician and grandson of George Lauder. He was educated at Phillips Exeter Academy, graduating in 1922, and graduated from Yale University in 1926 with a Bachelor of Arts degree. He then worked for a few years as a reporter for the Brooklyn Eagle newspaper.
In 1929 Greenway became a partner in the Franco-Anglo-American Zoological Expedition to Madagascar. The expedition was sponsored by the Muséum national d'histoire naturelle in Paris, the British Natural History Museum in London, and the American Museum of Natural History (AMNH) in New York City, and led by French ornithologist Jean Delacour. Greenway took part in the expedition from April to August 1929, after which he and Delacour left Madagascar for Delacour’s fifth expedition to Indochina, where they collected zoological specimens in Tonkin and Annam.