The club was founded in the early 20th century as RFC Bressoux, registered with the Belgian FA under matricule 23, but renamed in 1992 to Royale Union Liégeoise or RUL after a merger.

As a result, the club now carried matricule 167 (as 23 now belonged to Boussu Dour Borinage) and was able to immediately jump three levels and started the 2014–15 season in the Belgian Second Division.

With the Belgian league reform of 2016, the club dropped back to the third level but managed to achieve promotion twice in succession in 2019–20 and 2020–21 to reach the 2021–22 Belgian First Division A, bringing back top division football to the city of Seraing after 25 years.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.