It was founded in 1912 as Olympic Club de Charleroi. The next year the club registered to the Belgian Football Association to become the matricule n°246. Between 1972 and 1982 the club was named R.O.C. de Montignies-sur-Sambre. In 2000 the club merged with R.A. Marchienne and changed its name from Royal Olympic Club de Charleroi to its present name.
O.C. de Charleroi first appeared in the second division in 1936 and it won its league eight points ahead of U.S. du Centre, a rival club located nearby Charleroi. It then played in the first division until 1963 (except for the 1955–56 season), joined at that level by the rival Charleroi S.C. in 1947. Olympic finished 3rd in 1939 and then second in 1947. The club had a short come back in the first division in 1967–68 and in 1974–75. In 1981 Olympic was relegated to the third division.