[5] The first team would start in the Régional 1, the sixth tier of French football, where Grand Calais Pascal FC had been playing prior to the merger.

[6][7] On 18 November 2023, in the seventh round of the 2023–24 Coupe de France, Calais secured a 2–1 victory over ESC Longueau thanks to stoppage time goals from Claudio Beauvue and Axel Prohouly, setting up a match against Ligue 2 side Caen in the following round.

They went on to defeat both Béthune [Fr] and Arras in penalty shoot-outs to secure Championnat National 3 football.

RC Calais finished top of Régional 1 Group C. It contested the play-offs against Stade Bethunois and Arras FA.

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