Having finished as runners-up in the French second tier last season, Lens were looking forward to taking their place alongside the elite with fellow promoted sides Metz and Caen.
However, financial troubles have dogged their preparations and their place in Ligue 1 had been suspended due to investment from Azerbaijani investor Hafiz Mammadov failing to appear.
After having their initial appeal rejected by the Direction Nationale du Controle Gestion - French football's watchdog - Lens confirmed they would appeal to the French National Olympic and Sports Committee (CNOSF).
And upon hearing their case, Lens have announced the CNOSF upheld their appeal, thus approving their promotion.
"The National Olympic and Sports Committee French (CNOSF) issued on Friday evening, a favourable opinion on the promotion of Racing Club de Lens to Ligue 1," a statement released on their official website read.
The news will come as a blow to Sochaux, who have been monitoring the situation hoping they could be reinstated to the top flight after their relegation last season.
Lens are due to open their Ligue 1 campaign away at Nantes on August 9.