Phoenix Suns (2017–2019) 2017–18 season On June 22, 2017, Jackson was selected by the
Phoenix Suns with the fourth pick in the
2017 NBA draft, being their second straight selection at pick #4 after
Dragan Bender. After he was drafted 4th by Phoenix, it was reported that Jackson had cancelled his workout with the
Boston Celtics, who held the 3rd pick after trading the #1 pick to the
Philadelphia 76ers, just as the Celtics management and staff were midway to
Sacramento to meet him, something that reportedly angered Celtics general manager
Danny Ainge, although Ainge denied that it factored into his decision to not draft Jackson. When questioned on it,
Ryan McDonough, the general manager of the Suns, did not deny any collusion between the Suns and Jackson's representatives to dissuade the Celtics from drafting Jackson. However, Jackson attributed the situation to nothing more than poor timing and an inability to reschedule for a more proper date. Jackson would sign his rookie scale contract on July 3, 2017. During the
2017 NBA Summer League, Jackson recorded averages of 17.4 points, a team high 9.2 rebounds, 1.6 assists, 1.2 steals and 1.0 blocks per game at 35.0 minutes per game in the five games (out of the team's six total) he played there, which earned him All-Summer League First Team honors alongside
Lonzo Ball,
Dennis Smith Jr.,
John Collins and
Caleb Swanigan. Jackson made his NBA debut as starting power forward for the Suns on October 18, 2017. During the third game of the season, Jackson made an inappropriate, menacing gesture with his hand towards the fans of the
Los Angeles Clippers, which would result in him being fined $35,000 on October 24, 2017. He would start for the Suns at power forward before returning to his more natural small forward position (albeit off the bench) on October 23, 2017, in a win against the
Sacramento Kings. On November 29, 2017, Jackson scored a then season-high 20 points in a loss to the
Detroit Pistons. Jackson would be put back into a starting position on December 7 at shooting guard after
Devin Booker's injury the previous game against the
Toronto Raptors. Jackson recorded his first double-double of his professional career on January 7, 2018, with 17 points, and season highs of 10 rebounds and 5 assists in a 114–100 win over the
Oklahoma City Thunder. After missing their next game against the
Houston Rockets due to a strained right hip, he returned to the starting lineup as a small forward on January 14, recording a new career-high 21 points in a blowout loss to the
Indiana Pacers. He tied that career high on January 31 in a 102–88 win over the
Dallas Mavericks before putting up a new season high with 23 points on February 4 in a 115–110 loss to the
Charlotte Hornets. On his 21st birthday, Jackson would have his best all-around game in his rookie season with 20 points, 7 rebounds, 5 assists, 1 steal and a season-high 4 blocks in a 123–113 loss on the
Denver Nuggets. He would break the previous season high in points with 29 scored on February 28 in a 110–102 win against the
Memphis Grizzlies. On
St. Patrick's Day, Jackson would break that career high with the first 30-point game of his professional career with 36 points scored while coming off the bench in a 124–109 loss against the
Golden State Warriors. On March 20, 2018, he would record a double-double of 15 points and a career-high 11 rebounds in a loss to the
Detroit Pistons. On May 22, 2018, he was named to the
NBA All-Rookie Second Team.
2018–19 season Before being named an NBA All-Rookie Second Team member, Jackson was the team's representative for the 2018 NBA Draft Lottery; the Suns won the #1 pick for the first time in franchise history on May 15, 2018. He later joined the top pick,
Deandre Ayton, and the Suns' other rookies and young players for the
2018 NBA Summer League. During the entire pre-season, Jackson was forced into the role of the leading shooting guard, trying to replicate the role of
Devin Booker, who was out at the time due to finger surgery. In the season debut on October 17, 2018, Jackson returned to the bench for the team, as he recorded 18 points on 7-of-11 shooting, including 3-of-4 three-point shooting, in a 121–100 blowout win over the
Dallas Mavericks.
Memphis Grizzlies (2019–2020) On July 7, 2019, the Suns traded Jackson to the
Memphis Grizzlies. On September 27, the Grizzlies assigned him to the
Memphis Hustle, their
NBA G League affiliate, for the start of the season. Jackson played in 26 games for the Hustle before being called up by the Grizzlies, averaging 20.3 points, 7.5 rebounds, 4.3 assists, 1.4 blocks and 1.3 steals per game was named Midseason All-NBA G League for the Western Conference.
Detroit Pistons (2020–2022) On December 1, 2020, Jackson signed with his hometown team, the
Detroit Pistons. He made his debut for the team on December 23, logging 19 points and six rebounds in a 101–111 loss to the
Minnesota Timberwolves. On April 1, 2021, Jackson scored a season-high 31 points, alongside four assists, in a 120–91 win over the
Washington Wizards. He ended the 2020–21 season averaging a career-high 13.4 points per game. On January 3, 2022, Jackson scored a season-high 24 points, alongside five rebounds, in a 115–106 win over the
Milwaukee Bucks.
Sacramento Kings (2022) On February 10, 2022, Jackson and
Trey Lyles were acquired by the
Sacramento Kings in a four-team trade that sent
Marvin Bagley III to the Pistons. The move reunited Jackson with former Suns teammates
Richaun Holmes and
Alex Len. On August 31, 2022, Jackson signed with the
Toronto Raptors. He was waived on October 14.
Stockton Kings (2023) On January 24, 2023, Jackson signed with the
Stockton Kings. He was waived four days later. ==Career statistics==