Sir Alex Ferguson

Before transforming Manchester United over 27 seasons, Sir Alex Ferguson won three Scottish titles and the 1983 European Cup Winners' Cup with Aberdeen—the last club outside the Old Firm to win the Scottish top flight. At Old Trafford, he rebuilt multiple title-winning generations to capture 38 trophies, including 13 Premier League crowns, 5 FA Cups, and 2 UEFA Champions League titles (highlighted by the 1998–99 Treble).