The 2020–21 FC Chambly Oise season was the club's 31st season in existence and its second consecutive season in the second division of French football. In addition to the domestic league, Chambly participated in this season's edition of the Coupe de France. The season covered the period from 1 July 2020 to 30 June 2021.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.