Ty Jacob "T. J." Leaf (born April 30, 1997) is an American-Israeli professional basketball player for the Indiana Pacers of the National Basketball Association (NBA). After playing one season of college basketball for the UCLA Bruins, he was selected by the Pacers in the first round of the 2017 NBA draft with the 18th overall pick.
Leaf was named an All-American as a high school senior in 2016. As a UCLA freshman in 2016–17, he earned first-team all-conference honors in the Pac-12. He also played for Israel's Under-18 junior national team at the 2015 FIBA Europe Under-18 Championship B Division.