Racing Club de Lens (French pronunciation: ​[ʁasiŋ klœb də lɑ̃s]; commonly referred to asRC Lens or simply Lens) is a French association football club based in the northern city of Lens in the Pas-de-Calais department. Its nickname, sang et or (English: blood and gold), comes from its traditional colours of red and gold. Their primary rivals are their northern neighbors Lille OSC, with whom they contest the Derby du Nord.

1905, Lens. On the place Verte (the actual place de la République), students are playingfootball. They do not yet know that they are writing the first lines of the history of the Racing Club de Lens. Why this name? Football was invented in England, so it was good to have a club with an Anglo-Saxon name. Moreover, the youth of that time were following the Racing Club de Roubaix and the Racing Club de France.

The first board was formed by the parents of those teenagers under the name of Racing club lensois, before the club would officially be registered under the name Racing Club de Lens in 1906. The club originally played in green, as the club was born on the place Verte, and the black, for the omnipresence of coal mining in the region.

Between 1907 and 1912, the players were forced to change sports grounds a couple of times, before settling at the actual parc des Glissoires, between Avion and Lens.

During World War I, the club’s activities were silenced, before restarting in 1919. Lens was then playing in sky blue.