Jaylen Marselles Brown is an American professional basketball player for the Boston Celtics of the National Basketball Association. He played one year of college basketball for the California Golden Bears and was named first-team all-conference and Pac-12 Conference Rookie of the Year. Declaring for the 2016 NBA draft following his rookie season, Brown was selected by the Celtics with the third overall pick. As a professional player, he divided his time between the position of point guard and small forward. Brown was a three-time NBA All-Star and six-time Eastern Conference finalist with Boston. He helped the Celtics reach the 2022 and 2024 NBA Finals, winning the championship and the Finals MVP award in the latter.

Brown made his Celtics debut on October 26, 2016, in a 122–117 season-opening win over the Brooklyn Nets, scoring nine points on 3-of-4 shooting while also adding two blocks over 19 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 then career-high 20 points in a 128–98 win over the Orlando Magic.  Brown helped the Celtics earn the No. 1 seed in the Eastern Conference before helping them advance to the Eastern Conference Finals, where the Celtics lost to the Cavaliers in five games. Brown had a productive rookie season, with his role off the bench continuing to develop as the year progressed. Brown averaged 17.2 minutes on the court, 6.6 points, 2.8 rebounds and 0.8 assists in 78 games and 20 starts. He was named to the NBA All-Rookie Second Team at the end of the season.