Walker was born and educated in Moose Jaw, Saskatchewan to a Canadian father and a Polish mother. His father, Richard Walker, was judged by his son to be "a man of good ability and excellent judgment", of a "calm, contemplative and philosophical" turn of mind, but "He lacked energy and had no great aptitude for affairs". His mother, Janina Lutkiewicz, was more driven, possessing "very strong character, remarkable energy, high ambition and unusual ability". Her ambition was transmitted to her first-born child, who applied himself to his studies while assisting his parents with their farm. His cousin Roger Lutkiewicz was a Squadron Leader in the Polish Air Force and later became an influential Polish politician.