Uiagalelei, who is of Samoan descent, was born in Bellflower, California.
His older brother DJ Uiagalelei is a quarterback for Florida State.
Matayo attended St. John Bosco High School.
[3] Uiagalelei accepted a scholarship from Oregon in December 2022[4] and enrolled early in 2023.
[6] He was rated as the true freshman most likely to play for the 2023 Oregon Ducks football team.