Greg Arnold was born in the small lakeside village of Meota, Saskatchewan in 1916. After the Second World War, following discussions with Alberta artist and educator Ron Spickett about attending art school, he enrolled as a mature student in the art program at the Provincial Institute of Technology and Art (now the Alberta College of Art) in Calgary. He graduated in 1950 and worked for ten years as a commercial designer while he continued his art education. As part of his studies, he carried out visits to England (1956) and Florence, Italy (1957). Arnold returned to ACA in 1962 as an instructor, teaching advertising art, design, compositions and crafts, staying with the College until 1968. He was actively involved in the Calgary art scene and served as president of the Alberta Society of Artists from 1962 to 1963.
During his six month trip to Florence as a student, Arnold was impressed by the “old world” environment and how the sense of history and time contrasted with the newness of the prairies. He created a large group of watercolours and drawings inspired by the patterning of the ironwork and the architecture that he saw there and later used the ideas suggested by these to create large abstractions. Strongly interested in abstract geometric form, Arnold began creating large plywood constructions in 1965, alongside his other artworks made in a multitude of other media.
His art was exhibited widely, including notably in the First Biennial of Canadian Painting, organized by the National Gallery in 1955. A large retrospective exhibition of his paintings and constructions was shown in 1989 at the Triangle Gallery in Calgary.