Rowan Alexander "RJ" Barrett Jr. (born June 14, 2000) is a Canadian professional basketball player for the Toronto Raptors of the National Basketball Association (NBA). He was selected third overall in the 2019 NBA draft by the New York Knicks after one year with the Duke Blue Devils.

Born in Toronto as the son of former basketball player Rowan Barrett, Barrett shone at St. Marcellinus Secondary School in Mississauga, Ontario, before transferring to Montverde Academy in Montverde, Florida. He was a five-star recruit and the consensus top recruit in the 2018 class, earning Naismith Prep Player of the Year and Gatorade National Player of the Year accolades in his final high school season whilst playing as a shooting guard a majority of the season. He was ranked the top player in his class by all recruiting services and was the first player since LeBron James to sweep all major awards in high school and win the national championship.

With the Canadian national under-19 team, Barrett was named MVP at the 2017 FIBA Under-19 Basketball World Cup after leading his team to a gold medal. He debuted for the senior team during qualification for the 2019 FIBA World Cup.