Justise Jon Winslow was born on March 26, 1996 in Houston to Robin Davis and Rickie Winslow. Winslow, whose nicknames are "JWins", "JDubb", "Jus-Blaze" and "Rubdi", has three older brothers and one older sister. His father played collegiately at the University of Houston and was a member of the Phi Slama Jama team that also featured Hakeem Olajuwon and Clyde Drexler. Winslow's father was a first-round pick of the Chicago Bulls in 1987. One of Winslow's brothers, Josh, played college football at Dartmouth, while his sister, Bianca, played basketball at the University of Houston. Winslow has been involved in a number of charitable efforts, including founding the Robin's House Foundation along with his family. The foundation's mission is to "encourage and guide children and young adults to discover their highest potential through education, recreation and community outreach." Winslow also hosts basketball camps in Houston and helped to raise money after Hurricane Harvey hit the city in 2017. In high school, Winslow was a two-time Gatorade Texas Boys Basketball Player of the Year, and he was selected to the McDonald's All-American Game in 2014. A five-star recruit, Winslow opted to play collegiately at Duke University. Follow Winslow on Twitter and Instagram @IAmJustise.