The Revolutionary Socialist Party (Luxembourgish: Revolutionär Sozialistesch Partei, French: Parti Socialiste Révolutionnaire), abbreviated to RSP, was a in Luxembourg. At its start, it was a Trotskiyst group active in the late sixties in the . When the majority of students' group became Maoist and was transformed in the , the Trotskyist minority split and founded the Revolutionary Communist League (French: Ligue Communiste Révolutionnaire) in September 1970. It published Klassenkampf starting in 1970, and in December 1984 was renamed the Revolutionary Socialist Party and published Sozialistesch Aktioun until 1992.