On June 23, 2016, Brown was selected by the Boston Celtics with the third overall pick in the 2016 NBA draft.
On July 27, he signed his rookie scale contract with the Celtics after averaging 16.0 points, 6.2 rebounds and 2.3 steals in six Summer League games.
He made his debut for the Celtics in their season opener on October 26 against the Brooklyn Nets, scoring nine points on 3-for-4 shooting, while adding two blocked shots in 19-plus minutes.
In his first career start on November 3, Brown scored 19 points in a 128–122 loss to the Cleveland Cavaliers.
On January 27, 2017, he scored a career-high 20 points in a 128–98 win over the Orlando Magic.
Brown helped the Celtics claim the No.
1 seed in the Eastern Conference, before helping them advance through to the Eastern Conference Finals, where they were defeated by the Cavaliers in five games.
Brown had a productive rookie season in 2016–17, with his role off the bench continuing to develop as the year went on.
He appeared in 78 games for the Celtics during the regular season, with 20 starts.
He averaged 17.2 minutes on the floor, 6.6 points, 2.8 rebounds and 0.8 assists.
At the season's end, he was named to the NBA All-Rookie Second Team.
On June 23, 2016, Brown was selected by the Boston Celtics with the third overall pick in the 2016 NBA draft. On July 27, he signed his rookie scale contract with the Celtics after averaging 16.0 points, 6.2 rebounds and 2.3 steals in six Summer League games. He made his debut for the Celtics in their season opener on October 26 against the Brooklyn Nets, scoring nine points on 3-for-4 shooting, while adding two blocked shots in 19-plus minutes. In his first career start on November 3, Brown scored 19 points in a 128–122 loss to the Cleveland Cavaliers. On January 27, 2017, he scored a career-high 20 points in a 128–98 win over the Orlando Magic. Brown helped the Celtics claim the No. 1 seed in the Eastern Conference, before helping them advance through to the Eastern Conference Finals, where they were defeated by the Cavaliers in five games. Brown had a productive rookie season in 2016–17, with his role off the bench continuing to develop as the year went on. He appeared in 78 games for the Celtics during the regular season, with 20 starts. He averaged 17.2 minutes on the floor, 6.6 points, 2.8 rebounds and 0.8 assists. At the season's end, he was named to the NBA All-Rookie Second Team.
Jaylen Brown