FC Differdange 03

It was founded in 2003, by a merge of 2 clubs from the city of Differdange: FA Red Boys Differdange and AS Differdange. When the clubs merged, in time for the 2003–04 season, Red Boys was languishing in the bottom half of the Division of Honour, while AS was in mid-table position in the third tier of Luxembourgish football. The new club took Red Boys league position, and was promoted back into the National Division in the 2005–06 season, when the top division was expanded from twelve clubs to fourteen. Red Boys Differdange had previously been one of the largest and most successful teams in Luxembourgish football, having won the Luxembourg Cup more times than any other team (15). During the 1920s and 1930s, Red Boys competed with Spora Luxembourg for dominance of Luxembourgish football. Red Boys was the more successful of the two, and won thirteen trophies in as many years between 1923 and 1936. Despite the staunch competition (Spora won 8 trophies in the same period), this record has never been matched. In the 2011–12 UEFA Europa League Differdange 03 progressed to the 3rd qualifying round of the competition after they eliminated Levadia Tallinn 1–0 on aggregate, one of the club's most famous European victories and one of the most historic victories for a club from Luxembourg has ever had in European Competitions. In the 3rd qualifying round they met Olympiacos Volos and lost 3–0 in both legs, 6–0 on aggregate. However, as Olympiacos Volos were presumably involved in a…

National Division (8) as SC Differdange Runners-up (1): 1910–11 as Red Boys Differdange Winners (6): 1922–23, 1925–26, 1930–31, 1931–32, 1932–33, 1978–79 Runners-up (10): 1926–27, 1933–34, 1934–35, 1957–58, 1973–74, 1975–76, 1979–80, 1980–81, 1983–84, 1984–85 as Differdange 03 Winners (2): 2023–24, 2024–25 Runners-up (5): 2008–09, 2014–15, 2016–17, 2021–22, 2025–26 Luxembourg Cup (21) as Red Boys Differdange Winners (15): 1924–25, 1925–26, 1926–27, 1928–29, 1929–30, 1930–31, 1933–34, 1935–36, 1951–52, 1952–53, 1957–58, 1971–72, 1978–79, 1981–82, 1984–85 Runners-up (9): 1923–24, 1931–32, 1934–35, 1947–48, 1949–50, 1954–55, 1969–70, 1976–77, 1985–86 as AS Differdange Runners-up (1): 1989–90 as Differdange 03 Winners (7): 2009–10, 2010–11, 2013–14, 2014–15, 2022–23, 2024–25, 2025–26 Runners-up (1): 2012–13