Okafor had been heavily recruited before high school and was at the top of the recruiting rankings for several years. He played high school basketball in Chicago, Illinois for Whitney M. Young Magnet High School, where he earned high school national player of the year awards from McDonald's, "USA Today" and "Parade". At the 2012 FIBA Under-17 World Cup, he earned the Tournament MVP for the gold medal-winning USA team. In 2013, Okafor led Whitney Young to the 2013 Chicago Public High School League (CPL) city championship. He was an All-American as a junior in 2013. The following summer, he was an All-Tournament team selection at the 2013 FIBA Under-19 World Cup, for the gold-medal Team USA. Following his senior season, he earned broad All-American recognition and was named national player of the year by "Parade", "USA Today" and McDonald's among other players. He signed with Duke as a package with Tyus Jones, with widespread recognition as the preseason Collegiate National Player of the Year.