Communist Workers League (in Spanish: Liga Obrera Comunista) was a Trotskyist group in Spain.

It was included in the Spanish registry of political partis held by the Ministry of Interior on September 19, 1977 LOC published Prensa Obrera 1976-1990.

The Communist Workers League left the International Committee of the Fourth International on October 25, 1985, when they refused to attend a meeting duly summoned by the International Committee of the Fourth International: they argued that the meeting was not called by the leader of the British Workers Revolutionary Party whom they supported.

The Communist Workers League signed joining IC-Verds and United Left in 1991.

As of this date there are no known public events as LOC but they continued publishing a magazine, "Marxismo", whose last issue appeared in March 1999.