Koninklijke Sint-Niklase Sportkring Excelsior was a Belgian football club from the town of Sint-Niklaas that merged with KSC Lokeren in 2000, establishing K.S.C. Lokeren Oost-Vlaanderen.
It was created in 1920 as F.C. Beerschot but the name changed a year later to V.V. Beerschot Sint-Niklaas. The club then registered to the Belgian FA as Sint-Niklaassche S.K. in 1922 and received the matricule n°221. Right after World War II, Sint-Niklaassche qualified for the first division but only stayed at that level for two seasons. Following the relegation, the name changed to Sint-Niklaasse S.K. and then to K. Sint-Niklase S.K. in 1974.