İLE KURULMUŞTUR As a junior, Williamson averaged 36.8 points, 13 rebounds, 3 steals, and 2.5 blocks per game. Entering the season, he was among 50 players selected to the Naismith Prep Player of the Year Award watch list. Starting in the 2016–17 season, Williamson was propelled into the national spotlight for his viral highlight videos. He made his season debut on November 15, 2016, recording 42 points and 16 rebounds in a win over Cardinal Newman High School. In the same month, his highlights drew the praise of NBA player Stephen Curry. On November 24, Williamson erupted for 50 points, including 10 dunks, along with 16 rebounds and 5 blocks versus Proviso East High School at the Tournament of Champions. In a 73–53 victory over Gray Collegiate Academy at the Chick-fil-A Classic on December 21, he posted a tournament-record 53 points and 16 rebounds, shooting 25-of-28 from the field. On December 30, Williamson recorded 31 points and 14 rebounds to win most valuable player (MVP) at the Farm Bureau Insurance Classic. On January 15, 2017, he received nationwide publicity after rapper Drake wore his jersey in an Instagram post.
Williamson surpassed the 2,000-point barrier on January 20, when he tallied 48 points against Oakbrook Preparatory School. On February 14, he led Spartanburg Day past Oakbrook Prep for their first SCISA Region I-2A title, chipping in a game-high 37 points in a 105–49 rout. Williamson broke the state record for most 30-point games in a season, with 27 by the end of the regular season.[25] He repeated as SCISA Region I-2A Player of the Year. High school sports website MaxPreps named him National Junior of the Year and to the High School All-American first team, while USA Today High School Sports gave him All-USA first team recognition. On April 22, 2017, Williamson recorded 26 points and 7 rebounds for his AAU team SC Supreme in a loss to highly touted recruit Romeo Langford and Twenty Two Vision at an Adidas Gauntlet tournament. In June, he appeared on the cover of basketball magazine Slam. Williamson, in a highly publicized AAU game on July 27, scored 28 points and led SC Supreme to a 104–92 win over 2019 class recruit LaMelo Ball and Big Ballers at the Adidas Uprising Summer Championships. In August, he was named MVP of the 2017 Adidas Nations camp after averaging 22.5 points and 7.2 rebounds through 6 games.
In his senior season, Williamson averaged 36.4 points, 11.4 rebounds and 3.5 assists per game.[33] He debuted on November 15, 2017, erupting for 46 points and 15 rebounds in a 70–62 loss to Christ School.[34] In his home opener on November 21, he recorded 29 points and 11 rebounds, leading the Griffins to a 70–55 win over Hammond School.[35] In the game, Williamson bruised his left foot, which sidelined him for over a month.[36] While recovering, he commented, "It's really been a time to grow mentally."[37] Williamson made his return from the injury on January 11, 2018, scoring 31 points in a 71–62 victory over Asheville Christian Academy.[38] On January 13, in a nationally televised game at the Hoophall Classic, he scored 36 points as his team lost to Chino Hills High School.[39] Williamson tallied 30 points and 13 rebounds in his final home game on February 8, a 58–54 win over Greensboro Day School.[40] On February 17, he posted 37 points, 10 rebounds, and 5 steals, while scoring his 3,000th career point, versus Spartanburg Christian Academy at the SCISA Region I-2A tournament.[41] One week later, Williamson guided Spartanburg Day to its third consecutive SCISA Region I-2A championship after recording 38 points against Trinity Collegiate School.[42]
On March 28, Williamson played in the 2018 McDonald's All-American Game, where he scored 8 points in 17 minutes before leaving with a thumb injury.[43][44] The injury also forced him to miss the Jordan Brand Classic and Nike Hoop Summit in the following month.[45] For his 2017–18 high school season, Williamson was named to the USA Today All-USA first team and MaxPreps All-American second team.[46][47] He additionally earned South Carolina Mr. Basketball recognition and was runner-up for Mr. Basketball USA.[48][49]
Wofford offered Williamson his first college basketball scholarship when he was a freshman in high school.[50] In the summer of 2015, Williamson emerged with the South Carolina Hornets AAU team as one of the top players in his class.[51] By the end of his sophomore season, he received offers from 16 NCAA Division I programs, including Clemson, Florida, and South Carolina, but was not planning on making a decision until his senior year.[11] In the summer of 2016, Williamson was drawing the most attention from Clemson, Florida, North Carolina, and South Carolina.[52] On August 30, 2016, he received a scholarship offer from Duke.[53] Williamson was also offered a football scholarship by Eric Mateos, tight ends coach for LSU, but did not show interest.[54] Entering his junior season, he was a consensus five-star recruit and was ranked the number one player in the 2018 class by recruiting service 247Sports.[55] In December 2016, ESPN recruiting director Paul Biancardi touted Williamson as "probably the best player in terms of production" in his class.[3] By 2018, most recruiting experts predicted that he would play for Clemson.[56]
In a live ESPN telecast on January 20, 2018, Williamson committed to Duke.[57][58] He explained the decision, "Duke stood out because the brotherhood represents a family. (Mike Krzyzewski) is just the most legendary coach that ever coached college basketball. I feel like going to Duke University, I can learn a lot from him."[58] Duke, who had landed RJ Barrett and Cam Reddish in addition to Williamson, became the first team to land the top three recruits in a class since modern recruiting rankings began.[59] His stepfather Lee Anderson remarked that Clemson lost a "mile-and-a-half lead" in recruiting Williamson.[60] Despite having three of the country's top recruits on their roster, Duke was unable to win the 2019 NCAA Tournament when they lost to Michigan State by one point in the East