Peter McIntyre was born and educated in Dunedin before travelling to London in the early 1930s to study at the Slade School of Fine Arts. After graduating, McIntyre worked as a free-lance commercial artist until 1939, when he enlisted in the Second New Zealand Expeditionary Force in England. He initially served as an anti-tank gunner until his talent as an artist was recognised by Major General Bernard Freyberg, who appointed him Official New Zealand War Artist in 1941.
McIntyre returned to New Zealand after the war and worked as a successful professional painter of portraits and landscape. A traditionalist by nature, McIntyre was critical of modernism and abstraction that proliferated Post War art, preferring a far more conservative approach than many of his well-known contemporaries. McIntyre was appointed an Officer of the Order of the British Empire for services to the arts in the 1970 New Year Honours.