Didier Agathe moved to Scotland in 1999 and played for Raith Rovers for a year before joining Hibernian on a temporary deal. His goal-scoring talent led Celtic to sign him in 2000 for £50,000, just as Scottish football was changing with Martin O’Neill taking over at Celtic. Agathe debuted in a match against St Mirren, which began a season that saw Celtic achieve the treble.
He made a strong impact in domestic competitions and was particularly effective in European matches. His key contributions during the 2003 UEFA Cup campaign included standout performances against Blackburn, Stuttgart, and Celta Vigo, where his speed and runs helped create scoring chances. In 2004, he notably neutralized star player Ronaldinho during a match against Barcelona, showcasing his skills at a high point in his career, along with being part of the team that reached Seville in 2003.
Despite these successes, Agathe faced criticism from fans on online forums, leading to heated debates about his performance. During the 2005/06 season, he struggled under manager Gordon Strachan due to his training habits and subsequent lack of appearances. Though linked to several clubs, he left Celtic in February 2006 after his contract was terminated.