Born in Wales, C. Denys Cook emigrated to Canada with his wife and children in 1957. Cook worked for the Alberta Government until 1974, when he began to pursue art full time. A self-taught artist, Cook did lapidary work, silver work, wood carving, and pottery.
While living in Edmonton Denys Cook was involved in the local arts scene. He joined the Edmonton Art Club in 1972 and was one of the founders of the Arts and Crafts Society of Alberta and the Canadian National Craft Council. His work was included in Edmonton Art Club exhibitions between 1973 and 1976, and he became an important figure in the Canadian wildlife art scene in the 1970s and 1980s. He left Edmonton for Victoria in 1980.