It was formed in 1991 from the clubs
Alliance Dudelange,
Stade Dudelange, and
US Dudelange. All three clubs had won the
National Division or the
Luxembourg Cup before, but each had fallen upon hard times, and the amalgamated club was expected to be more stable, in both a sporting and financial sense. Turning the club into a title-challenging team took a while. Stade Dudelange and US Dudelange had been in Luxembourg's third tier (the
1. Division), whilst Alliance Dudelange was struggling to remain in the second league (the
Division of Honour). The new club would take Alliance's place in the Division of Honour in the 1991–92 season. F91 was promoted in its first season, and soon established itself as a competent top-flight team, not finishing outside the top half of the table until 1996–97. Towards the end of the 1990s, Dudelange gradually improved, and brought to an end
Jeunesse Esch's era of dominance by storming to the 1999–00 league title by eleven points. In
2004–05, Dudelange won the title and competed in the
UEFA Champions League for the 2005–06 season. In the competition Dudelange became the first club in Luxembourg's history to reach the second qualifying round, after a remarkable victory over
NK Zrinjski (they lost 0–1 at home in the first leg, in the second leg they scored a goal in the 3rd minute of
stoppage time to equalize on aggregate, and then scored 3 more goals in extra time). However, Dudelange were easily beaten by
Rapid Wien in the second qualifying round. In the
2005–06 season, Dudelange completed the
league and
cup Double for the first time since the merger. They replicated this feat in the
2006–07 season, and won a fourth consecutive National Division title in
2007–08. In the
2012–13 UEFA Champions League, F91 Dudelange defeated
Tre Penne 11–0 on aggregate, earning them an appointment with Austrian champion
Red Bull Salzburg in the second round. They defeated Salzburg 1–0 in Luxemburg, and lost 3–4 in Salzburg, to win the tie on the away goal rule. For the first time in club history, Dudelange qualified for the third round of the competition, in which they were beaten 5–1 on aggregate by
Maribor. In
2013–14, Dudelange reclaimed the title with a 3–0 victory over
Fola Esch on the final day of the season. This earned the club a spot in the
2014–15 UEFA Champions League. In 2018, F91 Dudelange became the first Luxembourgish team to reach the group stage of a major European competition, after defeating
CFR Cluj 5–2 on aggregate in the
UEFA Europa League play-off round. Due to Dudelange's apparent
underdog status, daily newspaper
Gazeta Sporturilor regarded CFR's elimination as "the biggest shame in the history of Romanian football". Dudelange had also previously defeated Polish side
Legia Warsaw in the third qualifying round. The men from the Grand Duchy were drawn into a 'Group of Death', containing European powerhouses
AC Milan,
Olympiacos and Spanish side
Real Betis. The Luxembourgers did, however, managed to pick up a famous and hard-fought point, on the last matchday, when they drew 0–0 against Real Betis at the
Stade Josy Barthel. In 2019, Dudelange qualified for the
Europa League group stages for the second successive season after defeating
FC Ararat-Armenia in the play-off round in a penalty shootout. Dudelange fared much better in their second European group stage adventure, being drawn into a group with
Europa League stalwarts
Sevilla, Cypriot champions
APOEL and
Qarabağ of Azerbaijan. On the first group stage matchday, on 19 September 2019, Dudelange became the first ever team from Luxembourg to win a game in a European group stage after beating
APOEL 4–3 in
Nicosia. Dudelange, whose coach Emilio Ferrera had resigned only two days prior, came back from a 3–2 deficit to defeat the Cypriots. After losing their next four group matches, Dudelange faced Qarabag on the last matchday in
Baku, where they came within two minutes of recording another famous win before the Azeri side equalised in injury time. Dudelange finished bottom of the group with 4 points. ==Honours==