Collier grew up in Marietta, Georgia and attended Wheeler High School. His coach at Wheeler was his uncle, Larry Thompson.[1] Collier averaged 18 points, seven rebounds, seven assists, and two steals per game as a junior.[2] He played in the Nike Elite Youth Basketball League (EYBL) following the season and averaged 17.6 points, 5.1 rebounds, and 6.5 assists per game.[3] Collier suffered a meniscus injury in his knee while participating in workouts with the United States under-18 basketball team in May 2022, which caused him to miss the rest of the EYBL circuit.[4] He participated in the Curry Camp and was named the camp's MVP.[5]
Collier for his senior year averaged 19.6 points, 6.8 assists, 5.5 rebounds, and 2.2 steals while shooting 52 percent from inside the arc, 38 percent from 3-point range, and 77 percent from the free throw line.[6]
Collier was a consensus five-star recruit and one of the top players in the 2023 class, according to major recruiting services.[11][12] He was rated as the number one overall prospect for the 2023 class by ESPN and Rivals.[13][14] On November 16, 2022, Collier committed to playing college basketball for USC after considering offers from Cincinnati, Michigan, and UCLA.[15][16]
Collier enrolled at the University of Southern California in June 2023.[17] He started the Trojans' season opener against Kansas State and scored 18 points with three rebounds and six assists before fouling out of the game.[18]
Collier averaged 16.3 points, 4.3 assists and 1.5 steals per game. On April 10, 2024, Collier declared for the 2024 NBA draft, forgoing his remaining college eligibility.[19]
On January 26, 2025, Collier was named the starting point guard in place of Keyonte George.[23] On February 8, Collier set a new Jazz rookie record for assists in a half, totaling 10 in the first half against the Phoenix Suns.[24] On February 28, Collier recorded a career-high 14 assists in a 117–116 win over the Minnesota Timberwolves.[25] He was named February's Western Conference Rookie of the Month after averaging 11.5 points, 9.5 assists and 3.9 rebounds per month.[26] On March 31, in a game against the Charlotte Hornets, Collier surpassed John Stockton's previous record of 415 for the most assists recorded in a season by a rookie in Jazz franchise history.[27]
