Maroussi B.C. alternately translated as Marousi, Amaroussi, or Amaroussion, is a professional basketball club that is based in Marousi, a northern suburb of Athens, Greece. The club's full name is Gymnastikos Syllogos Maroussi Basketball Club, which is commonly abbreviated as G.S. Maroussi B.C.

The Greek B Basket League, or Greek B Basketball League, is a national basketball league in Greece. It is also known as the Second National Championship, B National Championship, Second National League, B National League, Third Division, and in Greek,. It is organized by the Hellenic Basketball Federation (E.O.K.).