Alfred J. Casson was born in Toronto and moved to Guelph, Ontario at the age of nine. At the age of 14, he moved to Hamilton where he studied at the Hamilton Technical School. At 16 he was apprenticed to Laidlaw Lithography Co. in Hamilton where he re-touched photographs and engraved zinc plates. In 1914 Casson was employed by Commercial Engravers Co. in Hamilton, moving back to Toronto in 1915 to work as a free-lance designer. In the evenings Casson attended the Toronto Central Technical School (1915-1917), the Ontario College of Art (1918-21) and attended private classes where he studied watercolour and oil painting.
Casson met Franklin Carmichael in 1915 while employed by Rous & Mann. From 1919 to 1926 they undertook several sketching trips together. During this time he met other members of The Group of Seven and assisted Carmichael with the formation of the Canadian Society of Painters in Watercolour in 1923. Casson was invited to the membership of The Group of Seven in 1926. Around 1924 his style had began to change and he began to focus on Ontario village scenes. Casson’s later works focussed on natural and botanical studies. He held the position of Art Director for Samson and Matthews Ltd. and was involved with the development of programs for the reproduction of artists’ works with The National Gallery of Canada. He continued to live in Toronto until his death in 1992 at the age of 93.