williams attended north high school. after playing in just one game as a freshman and averaging just 3.5 points as a sophomore, williams averaged 12.5 points, 10.9 rebounds and 3.3 blocks per game as a junior in 2009–10. as a senior in 2010–11, he averaged 22.1 points, 16.2 rebounds, 4.5 blocks, 2.0 steals, and 1.5 assists, leading north to a metro region championship and to the class 5a quarterfinals. he was named arizona state player of the year that season.