Russell was born to a Canadian mother, Matilda Shano of Newfoundland, and an American father, Milan Winslow Russel of New York. When Russell was four, the family moved to Calgary, Alberta. He received a Bachelor of Science in geology from the University of Alberta in 1927, and two graduate degrees from Princeton University: a Master of Arts in 1929 and a PhD in 1930. Russell did some of his earliest fieldwork in the 1920s in the Paskapoo Formation in southwestern Alberta, where he studied fossils.
Following graduation from Princeton, Russell served as an assistant palaeontologist with the Geological Survey of Canada from 1930 to 1936, and as an assistant geologist in 1937. From there, he worked as assistant director of the vertebrate section of the Royal Ontario Museum of Palaeontology (at the time, what is now the Royal Ontario Museum was divided into five museums: palaeontology, zoology, mineralogy, geology and archaeology). During the Second World War, he served in Canada and Europe with the Royal Canadian Corps of Signals; after the war, he transferred to the Canadian Militia, retiring with the rank of major.
Russell was director of the Royal Ontario Museum of Palaeontology from 1946 until 1950, when he joined the National Museums of Canada (chief, Zoology Section, 1950–56; director, Natural History, 1956–63; and acting director, Human History 1958–63). In 1963, he returned to the now amalgamated Royal Ontario Museum to lead the Life Sciences division, and a year later was appointed the museum’s chief biologist. At the same time he was appointed professor of geology at the University of Toronto. Russell officially retired in 1971, but continued to work out of his ROM office daily. He also returned to Alberta for fieldwork each summer until he was well into his eighties.
Russell's discoveries concerning dinosaurs and early mammals were particularly important. His 1965 paper, “Body Temperature of Dinosaurs and Its Relationship to Their Extinction,” marked the first time someone suggested that dinosaurs might have been warm blooded. An interest in material history also led him to research oil lamps, making original and fundamental contributions to the history of lighting and material culture in 19th-century North America. The books resulting from this research include A Heritage of Light (1968), Handy Things to Have Around the House (1979) and Every Day Life in Colonial Canada (1980).