The deal with Fortaleza was agreed last year as a pre-contract. Orozco has remained with the Colombian club for the season as he was unable to officially join United until July 13, when he reaches his 18th birthday.
Manchester United have been monitoring Orozco for some time, with the deal struck after his impressive performances caught the attention of the club's recruitment team. He captains Colombia at under-17 level and has drawn comparisons with Chelsea's Moisés Caicedo for his aggressive style of play and ball recovery ability.
Orozco is expected to be initially integrated into United's under-21 squad before being assessed for further opportunities, including possible minutes during pre-season.
The teenager visited Manchester at the end of December, touring Carrington and training with the academy, and made his senior debut for Fortaleza earlier this year, coming off the bench in a league match to gain first-team experience ahead of the move.
His arrival represents United's commitment to securing top South American talent at youth level, with the club's scouting operation having tracked Orozco across multiple age-group tournaments before making their approach.
The move was confirmed by Fabrizio Romano, who reported that United secured the deal for a fee of approximately $1m from Fortaleza, with United's lead scout coordinating the agreement. Orozco is seen as a long-term investment rather than an immediate first-team addition, though his development trajectory is considered exceptional for his age.
Orozco joins a pipeline of young South American talent that United have prioritised in recent windows, with the club's academy infrastructure positioned to fast-track his development in English football.