Ty Jacob Leaf (born April 30, 1997) is an Israeli-American professional basketball player for the Portland Trail Blazers of the National Basketball Association (NBA), on a two-way contract. After playing one season of college basketball for the UCLA Bruins, he was selected by the Indiana 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 began his NBA career with three seasons in Indiana before being traded to the Oklahoma City Thunder in 2020. He also played for Israel's Under-18 junior national team at the 2015 FIBA Europe Under-18 Championship B Division.