Alan Caswell Collier was born in Toronto in 1911. He studied at the Ontario College of Art under Franklin Carmichael & J.E.H. Macdonald and furthered his studies at the Art Student's League in New York.

Collier served in the Canadian Army 1943 - 1946.

He was elected to the Ontario Society of Artists in 1952 and became a teacher at the Ontario College of Art in 1955. Collier travelled often during his summers away from teaching on sketching trips across Canada, including the High Arctic to paint with the Polar Continental Shelf Project in 1984 and 1985.

Collier died in Toronto in 1990. His landscapes are known for their well-defined sense of form and strong compositions stripped of extraneous detail. His work is represented in the collection sof the National Gallery of Canada, the Art Gallery of Ontario, the Robert McLaughlin Gallery and the Frye Museum in Seattle, amongst others.