F91 Dudelange, or F91 Diddeleng, is a Luxembourgish professional football club based in Dudelange which plays in the Luxembourg National Division. It was formed in 1991 as a merger between three teams in the city — Alliance Dudelange, Stade Dudelange and US Dudelange. Domestically, it has since won the National Division on 15 occasions and the Luxembourg Cup eight times. F91 Dudelange qualified for the 2018–19 UEFA Europa League, becoming the first club from the country to reach the group stage of a European competition. Dudelange also made the 2019–20 UEFA Europa League group stage where they became the first team from Luxembourg to win a game in the group stage after a shock 4–3 victory over APOEL of Cyprus.