Hōjō Yoshitoki was born in 1163, who was the eldest son of Hōjō Tokimasa and his wife, Hōjō no Maki. At the time of his birth, he had an older sister, Hōjō Masako. Later on in the decade, he would have another brother, Hōjō Tokifusa, and a sister whose name remains unknown, but their birth dates are not known. The Hōjō clan was at that time in control of Izu, and Yoshitoki, being a Hōjō, was also a descendant of the Taira clan and also of the imperial family.