The 62-year-old replaces Bruno Lage, who was dismissed from his position following his side’s 3-2 home defeat to Qarabag in the Champions League on Tuesday, a game which the Portuguese side had led 2-0 in what was a shocking blow.
The former Chelsea boss returns to management less than a month after being dismissed by Fenerbahce is set to face his former sides in the league phase of the Champions League, with Benfica playing The Blues in a few week’s time.
Mourinho has had spells at Porto, Chelsea, Inter, Real Madrid, Manchester United, Tottenham Hotspur, Roma and now Benfica in a career that has spanned more than two decades in what has been one of the most legendary careers in football history.
After sacking Lage on Tuesday, Benfica president Rui Costa said the new manager must have the "profile of a winner" and they certainly have one in Mourinho who has won 21 major trophies, with his most recent success coming in the Conference League with Roma in 2022.
He returns to the Portuguese side, where he began his career resigned after nine league games due to a disagreement with the club’s then-president Manuel Vilarinho. His first game back at the Lisbon-based club is on Saturday at when they travel to 17th-placed AVS after collecting 10 points from their first four games.