Cullen married Yolande Du Bois on April 9, 1928. She was the surviving child of W.E.B. Du Bois and his first wife Nina Gomer Du Bois, whose son had died as an infant. The two young people were said to have been introduced by Cullen's close friend Harold Jackman. They met in the summer of 1923 when both were in college: she was at Fisk University and he was at NYU. Cullen's parents owned a summer home in Pleasantville, New Jersey near the Jersey Shore, and Yolande and her family were likely also vacationing in the area when they first met.