Jefferson was born on May 7, 1993 in Philadelphia, Pennsylvania. He grew up in Philadelphia, playing basketball from a very early age. Jefferson belongs to black ethnicity and is nationality is American. He was famous among all the basketball players and staffs in his high school, Friends Central.
Jefferson started to take part in tournaments since his high school. In his high school, he was trained by coach, Jason Polykoff. Game after game, he kept improving. He got his first reward as a basketball player in 2012 when he was named a McDonald's All-American. Jefferson finished his high school career with 1,569 points, 839 rebounds and 189 blocks. He entered college in 2012. In his first season playing for Duke Blue Devils of Duke University, he played total 32 games (starting 7 of them), averaged 4.0 points and 2.9 rebounds per game. He scored a career-high 14 points on 5-of-7 shooting from the field against Boston College . Jefferson was named a member of the All-ACC Academic Team in 2013-2014, just like in 2012-2013 season. The forward played all 35 games for the Devils (starting 26), averaging 6.5 points, 6.9 rebounds and 1.0 assists per game. In that season, he was second highest offensive rebounder of the team, with 101 offensive rebounds. He also scored his career-best 17 points against Kansas. His stats however decline a little bit in the season of 2014-2015 relative to his previous season. Nonetheless, his overall game play was good and he was the same ruthless Jefferson possessing the threat of scoring in the lane with both of his hands and providing tremendous support to his teammates like he used to do in his previous seasons. In 2014-2015 NCAA Championship, he averaged 6.4 points and 5.7 rebounds a game and his team Duke Blue Devils won the NCAA Championship that season. Currently he is enjoying his college basketball career. It will be no surprise that one day he will be in NBA draft and a renowned club will acquire him. Currently, he wears the number 21 jersey of Duke Blue Devils.
Jefferson has one brother and four sisters. His father was also a basketball player, who played at Delaware State from 1992 to 1994. As of 2015, there are not any rumors of Jefferson having a love affair. Hence, it implies, currently he doesn't have any girlfriend. He is not married yet and does not have any children.
Jefferson is a tall player with a height of 6 ft 8 inches and weight of 98 kg. His net worth and exact salary amount are unknown to general public, as he is just in the early phase of his career. Jefferson has won the 2015 NCAA Championship with Duke Blue Devils and was named a McDonald's All-American in 2012.