Playing in his third NBA season, Simmons saw action in 57 games for the 76ers, averaging 35.4 minutes per contest. The LSU product shot career-bests from both the field (58.0% FG) and the free-throw line (62.1% FT). Simmons posted averages of 16.4 points, 7.8 rebounds, 8.0 assists and a league-leading 2.1 steals per game. He was named to his second consecutive All-Star Game, in which he finished with 17 points, six rebounds, five assists and two steals as a member of Team LeBron. Simmons was also named to the NBA All-Defensive First Team for the first time in his career. On opening night against Boston on Oct. 23, Simmons started the season with 24 points, nine assists, and eight rebounds in a Sixers victory. He recorded his first of six triple-doubles on the season in a win over the Spurs on Nov. 22, finishing with 10 points, 13 assists and 10 rebounds. In a Dec. 7 win over the Cavaliers, Simmons hit the second three-pointer of his career and set a new career-high with 34 points in just 26 minutes. He matched that total in a win over the Nets on Jan. 20, finishing with a 34-point, 12-rebound, 12-assist triple-double, while also tacking on five steals and two blocks. In another triple-double effort, Simmons handed out a career-high 17 assists against the Nuggets on Dec. 23. He also added 16 points and 13 rebounds. The Melbourne, Australia native recorded a career-high seven steals on two separate occasions -- both 76ers victories. From Dec. 13 to Feb. 11, Simmons scored in double-figures in a career-best 29 consecutive games. In that span, he averaged 19.6 points, 8.7 rebounds, 8.3 assists and 2.2 steals per game. In a win over the Knicks on Nov. 20, Simmons drilled his first career three-pointer. At season's end, Simmons ranked ninth in the NBA in minutes per game, sixth in assists per game, first in steals per game, and fifth in triple-doubles. Simmons missed the 76ers' final nine games, including the playoffs, due to a knee injury. In September, Simmons was named to the All-NBA Third Team, his first career All-NBA selection.

Simmons started 79 games for the 76ers in his second healthy season in the NBA, averaging a career-high 16.9 points per game. On Jan. 2, he scored a season-high 29 points in a 132-127 win over the Phoenix Suns. The following month, he matched that 29-point high against the Portland Trail Blazers. The point guard averaged 7.7 assists per game, which was the sixth-highest rate in the NBA. On Jan. 11, Simmons dished out a career-high 15 assists against the Atlanta Hawks. Less than two weeks later, he matched that high with another 15-assist performance in a 122-120 victory over the San Antonio Spurs. Simmons' achievements were rewarded when he was named to his first All-Star Game. At the event, he scored 10 points in 17 minutes for Team LeBron. Simmons started 12 playoff games, averaging 13.9 points and 6.0 assists per game. He finished third in the league in total assists with 610.

Simmons made his highly anticipated NBA debut in 2017-18 after the previous season was wiped out by an injured foot. The delay proved to be worth the wait, as 2016's No. 1 overall draft pick consistently stuffed the stat sheet on his way to the NBA Rookie of the Year award. Simmons showed no lingering effects from the foot injury, playing 81 games and averaging 33.7 minutes per contest. He made use of excellent court vision and superb passing skills to average 8.2 assists per game, sixth in the league. Simmons also proved to be an adept rebounder, ranking among the top players at his position with 8.1 boards per contest. The ex-LSU Tiger also contributed as a scorer, registering 15.8 points per contest while shooting an efficient 54.5 percent from the field. Simmons was no slouch on the defensive end, either; he ranked ninth in the league with 1.7 steals per contest and second with 5.0 defensive win shares. Considering Simmons' diverse all-around game, it's no surprise that he racked up 12 triple-doubles on the season, trailing only Russell Westbrook and LeBron James for the top mark in the league. The rookie's emergence helped the Sixers qualify for the playoffs for the first time in six years, and they advanced to the Eastern Conference Semifinals before being eliminated by Boston. Simmons continued his strong play in the postseason, averaging 16.3 points, 9.4 rebounds, 7.7 assists and 1.7 steals over 10 games. His all-around brilliance as a 20-year-old earned Simmons a number of accolades. In addition to the Rookie of the Year award, he was named Rookie of the Month four times and Player of the Week twice while garnering a unanimous selection to the All-Rookie First Team.