Benjamin Dunkelman was the son of Polish-Jewish immigrants. His father was David Dunkelman, the founder of the Canadian men's retailers, Tip Top Tailors and his mother was a committed Zionist. Dunkelman and his siblings grew up on an estate, Sunnybrook Farm (now the site of Sunnybrook Medical Centre), northeast of Toronto. He attended Upper Canada College in Toronto. At 18 Dunkelman went off to work on a kibbutz in Palestine, at that time still under a British mandate. He returned to Toronto in 1932 to assist his father, but went again to Palestine in the late 1930s to develop new settlements.