Alexander-Walker declared for the NBA Draft in 2019 and was selected by the Brooklyn Nets with the 17th overall pick in the first round. He was then traded to the New Orleans Pelicans, where he began his professional career. As a versatile guard, Alexander-Walker quickly made a name for himself with his scoring ability, defensive skills, and playmaking. In 2022, he was traded to the Utah Jazz and subsequently to the Minnesota Timberwolves.