He led Yeshiva University to one of the longest winning streaks in NCAA Division III men's college basketball history.

As a child, his father Brad had played basketball against future NBA player Kiki VanDeWeghe, in college he had played basketball as a guard at the University of California, Santa Barbara, and as an adult he had performed public relations work for VanDeWeghe.

The older son, Jack, went on to play basketball at Yeshiva University, an NCAA Division III school.

[2] Ryan is a religious Orthodox Jew, keeps kosher, observes the Jewish Sabbath, and wears a yarmulke on his head—even while playing basketball.

[4][1][5] He also played for Earl Watson Elite, a premier Amateur Athletic Union (AAU) team.

However, late in his senior year of high school, by which time the family was living in another Los Angeles neighborhood, Sherman Oaks, Ryan surprised both of his parents when he told them that he would attend his brother's alma mater.

[1][8] In 2018–19, as a freshman, Turell averaged 20.2 points (tops in the Skyline Conference), 5.0 rebounds, 3.5 assists, and 1.4 steals per game.

[10] In 2021–22, as a senior, Turell averaged 27.1 points (leading all levels of college basketball), 5.5 rebounds, 2.7 assists, and 1.4 steals per game.

[9][10] In the 2022 NBA G League draft, the Motor City Cruise, the affiliate of the Detroit Pistons, selected Turell with the 27th pick in the First Round.

[11] In Turell's G-League debut during the regular season on December 27, 2022, he recorded a season-high 21 points, 2 rebounds and 1 steal as the Cruise fell 108 - 115 to the Capital City Go-Go.

In Turell's final game of the 2023 - 2024 season on March 29, 2024, he recorded a career-high 34 points while also grabbing 6 rebounds as the Cruise were defeated by the Raptors 905 104 - 109.