Gilbert is originally from Richmond, Virginia but moved to Lithonia, Georgia as he entered his teenage years. He was raised by his mother, Tamonica Alexander, and was not acquainted with his father, Alcuero Gilbert, who was incarcerated for about 10 years. Gilbert grew up playing football and started focusing on basketball in seventh grade.
High school career
Gilbert played basketball for Miller Grove High School near Lithonia. As a senior, he averaged 20.1 points, 5.8 assists, 5.5 rebounds and 4.3 steals, leading his team to a 31–3 record and the Class 5A state championship, his third state title in four years at Miller Grove. He helped his team reach the semifinals at High School Nationals despite sleeping one hour before the previous game. Gilbert was named Georgia Gatorade Player of the Year and Mr. Georgia Basketball. He was selected to play in the McDonald's All-American Game and Jordan Brand Classic. He left the Jordan Brand Classic early on April 15, 2016 after dislocating his left shoulder. In May, he underwent surgery on his shoulder. A four-star recruit and one of the best point guards in the 2016 class by the end of high school, Gilbert committed to UConn on July 4, 2015 over Louisville, Illinois, Syracuse and Texas.
College career
On November 11, 2016, Gilbert made his collegiate debut, scoring 14 points in a 67–58 loss to Wagner. Two games later, on November 17 versus Loyola Marymount, he suffered a torn labrum in his left shoulder that would require season-ending surgery. Gilbert subsequently redshirted the season. On November 23, 2017, as a redshirt freshman, he scored a then-career-high 16 points in a 71–63 win over Oregon at the Phil Knight Invitational. In his next game versus Michigan State, Gilbert injured his left shoulder. He attempted to play through the pain in his following game against Arkansas before being sidelined. On December 28, it was announced that he would miss the remainder of the season and likely undergo surgery. On December 5, 2018, during his sophomore season, Gilbert recorded a career-high 11 assists with no turnovers, five rebounds and three steals in a 90–63 victory over Lafayette. Three days later, he recorded a career-high 24 points, five steals and four three-pointers in a 79–71 loss to 11th-ranked Florida State at the Never Forget Tribute Classic. On January 26, Gilbert aggravated his left shoulder against Wichita State and missed five games. On March 7, in a 78–71 loss to Temple, he collapsed and began bleeding profusely from his nose after being hit in the face. He missed the final three games of the season with a concussion and right eye injury. He started in 23 of 25 games and averaged 12.6 points, 3.6 assists, 2.9 rebounds and 1.3 steals per game. On November 13, 2019, Gilbert scored a junior season-high 22 points in a 96–87 loss to Saint Joseph's. As a junior, he played 30 games for UConn, starting in 20, and averaged 8.5 points, 3.8 assists, 2.6 rebounds and 1.1 steals per game. Gilbert suffered from mental health issues, attending weekly therapy and taking daily medication to stabilize his mood. After the season, he announced that he was transferring from UConn. On March 28, 2020, Gilbert committed to play for Wichita State in his senior season. He is immediately eligible as a graduate transfer, filling a void at point guard and teaming up with Dexter Dennis in the backcourt.
