Leo was himself an accomplished tennis player and keen sportsman, and was a cadet officer and marksman in the Milton School Cadet Corp. He also played rugby and cricket for his school. Leo Ross suffered from peritonitis following a burst appendix in 1927 and was lucky to survive. He was ruled unfit for military service. In 1928, he joined the Native Affairs Department where he excelled in language and customs for both Shona and Ndebele peoples. He demonstrated a keen interest and respect for the African cultures and was widely respected by the indigenous people with whom he worked.