Bott’s father was of Austrian Catholic descent, while his mother was Jewish.
Raoul Bott was born on September 24, 1923, in Budapest, Hungary. He was a son of Rudolph Bott and Margit (Kovacs) Bott, who divorced soon after his birth. His mother remarried and Raoul lived with his mother and step father, who was a German speaking Czech, in Slovakia. His mother died in 1935 and Bott was raised by his stepfather in an upper-middle class environment. Bott and his family escaped to England in 1939 because of the tensions in Europe caused by the Nazis and their anti-Jewish policies. A year later, Bott and his family emigrated to Canada.