FC Differdange 03FC Differdange 03 was formed in 2003 through the merger of two clubs from the same industrial town in southern Luxembourg: FA Red Boys Differdange, founded in 1907, and AS Differdange, founded in 1921. The new club's name and lion emblem draw on the legacy of Red Boys, who, alongside CA Spora Luxembourg, dominated Luxembourgish football in the 1920s and 1930s, winning thirteen trophies in thirteen years between 1923 and 1936 and finishing their standalone history as the record holder for Luxembourg Cup wins.
After the merger, the new club inherited Red Boys' lower league position but returned to the top flight already in the 2005–06 season, when the league was expanded. Since 2006 the club has been led by president Fabrizio Bei, whose long tenure is widely credited as the foundation of Differdange's sporting rise. The team plays in red and white and hosts its home matches at the Stade Municipal de la Ville de Differdange, opened in 2012.
The club's loudest European chapter came in the 2011–12 UEFA Europa League. Differdange eliminated Estonia's Levadia Tallinn, and although they then lost 0–6 on aggregate to Greece's Olympiakos Volou in the next round, they advanced anyway: UEFA excluded the Greek club from the competition over a match-fixing scandal and handed Differdange the play-off round spot instead. There they faced Paris Saint-Germain — the furthest any Luxembourgish club has ever reached in European competition.
Domestically, the club has been among the country's strongest for years: it won back-to-back Luxembourg championships in the 2023–24 and 2024–25 seasons, and the 2025 league-and-cup double was its first since Red Boys' 1978–79 double. It has also lifted the Luxembourg Cup in 2010, 2011, 2014, 2015 and 2023, cementing its place among the most decorated clubs in modern Luxembourgish football.
