RC Calais had excellent results in the first editions of the Coupe de France, taking part in the quarter-finals of the competition in 1921, the last 8 in 1922 and the last 16 in 1923, 1924, 1925, 1926 and 1930.

Calais RUFC entered the international spotlight during their run to the final of the 1999–2000 Coupe de France, under Spanish coach Ladislas Lozano.

They eventually lost 2–1 to Nantes Atlantique in the final at the Stade de France in Paris on 7 May 2000, despite leading 1–0 at half-time.

[4][5] There was another creditable run in the 2005–06 Coupe de France, as Calais progressed through eight rounds, including a win over top-division Troyes, before losing narrowly in the quarter-finals, again to Nantes.

[citation needed] On 15 May 2010, CRUFC won the CFA 2 Group A by defeating Gravelines 2–0, with Alexandre Danset scoring both of the goals.

[7][8] Subsequently, the FFF gave them an Administrative relegation, meaning they would play the 2017–18 season at Regional level at best.