John Metchie III was born in Taiwan and lived in Ghana and Canada before moving to the United States to attend high school. He attended St. James School in Hagerstown, Maryland and spent a post-graduate year at the Peddie School in Hightstown, New Jersey. Upon completion of high school, Metchie, a 4-star recruit, committed to the University of Alabama to play college football.
Metchie appeared in 30 games for the Crimson Tide over three seasons. In those 30 contests, Metchie totaled 2,081 yards on 155 career receptions. Metchie found the end zone a total of 14 times at Alabama. His best season came in his 2021 junior season in which he totaled 1,150 scrimmage yards and scored 8 times.