Olaniyi was born in Brooklyn, New York. He attended a charter school, which did not have a basketball team, as a high school freshman before transferring to Newark East Side in Newark, New Jersey the following semester. Olaniyi did not begin playing basketball until eighth grade when a gym teacher pointed him towards the direction of AAU basketball. He played two years in AAU with the NJ Roadrunners. At Newark East Side, he played for head coach Anthony Tavares. With Olaniyi, the Newark East Side Red Raiders won county championships in 2014 and 2017, as well as a state title in 2015. In 87 high school games, Olaniyi recorded 928 points and 588 rebounds. In his junior season, he was named to the All-Group 4 First Team. He was named first-team All-State and All-Conference as a senior. Olaniyi was listed as a two-star recruit by ESPN as a small forward, with a 67 overall grade. ESPN ranked Olaniyi as the 11th-best recruit in the state of New Jersey and the 75th-best small forward.
College career
Olaniyi made his college debut on November 10, 2017, against Maryland, where he played 20 minutes and scored three points. On November 19, Olaniyi came off the bench and led Stony Brook with 16 points against #2 Michigan State, who the Seawolves led 25–17 in the first half. The game started a series of five double-digit games in a row off the bench for Olaniyi. In his first career start, he had a double-double with 10 points and 10 rebounds against Hartford. By season's end, Olaniyi found himself a regular member of the starting lineup, starting eight of the team's final nine games. He won the 2018 America East Rookie of the Year award after leading all freshmen with 7.8 points and 3.8 rebounds per game. He was named America East Rookie of the Week four times and was also named to the America East All-Rookie Team. In his sophomore season, Olaniyi averaged 16.8 points in Stony Brook's first four games before suffering a concussion in the team's home opener against Molloy. He missed two games and came off the bench against Quinnipiac in his return. On February 2, 2019, Olaniyi scored a new career-high 28 points against Hartford. In Stony Brook's America East quarterfinal loss to Binghamton, Olaniyi led all players with 27 points. He finished his sophomore season averaging 12.3 points per game and 5.9 rebounds per game with a 42.5 percent field goal rate. He was named to the Third-Team All-America East. Olaniyi broke out in his junior season. On December 7, 2019, he had a career game, scoring 30 points against Brown on 11-for-15 shooting. He scored his 1,000th career point in a 70–62 victory over Albany on January 18, 2020. The game was the last of four straight double-doubles in which Olaniyi scored at least 20 points with over 10 rebounds. Olaniyi had another career game on February 5 when he scored a career-high 33 points against UMass Lowell. On February 8, Olaniyi suffered a high ankle sprain versus New Hampshire and would miss five games; prior to the injury, he was averaging 19.7 points and 6.9 rebounds per game. He returned off the bench on March 3 against UMBC and re-entered the starting lineup in the 2020 America East Tournament, scoring 11 points against Albany in the quarterfinals and 19 points against Hartford in the semifinals. Olaniyi was named to the First-Team All-America East, ending his junior season averaging 18.0 points and 6.5 rebounds per game while shooting 43.5 percent from the floor and 36.1 percent from three. On March 28, 2020, Olaniyi officially declared for the 2020 NBA Draft. On May 17, he announced that he would transfer to Miami for his senior season.
College statistics
Personal life
Olaniyi was born to Festus and Ruth Olaniyi and has five siblings. Olaniyi was the first member of his family to be a natural born citizen of the United States after his parents immigrated from Nigeria. Olaniyi cites Kobe Bryant and Jimmy Butler as personal influences on his basketball career.
