[1] Monedero studied economics, achieving a degree in political science and sociology in the Universidad Complutense de Madrid (UCM).

[3][4] Juan Carlos Monedero was a political advisor to Spanish politician Gaspar Llamazares from 2000 to 2005, when he was the General Coordinator of United Left.

He has published columns in newspapers such as Público, written articles in El País, and collaborated in political debate programmes such as La Tuerka and Fort Apache, presented by Pablo Iglesias.

[11] In January 2014, Monedero participated in the Podemos project with other activists and intellectuals such as Pablo Iglesias, seeking to unite left-wing forces in Spain against the current European political and financial system.

[12][13] According to El Mundo, Monedero supposedly received up to €1.5 million from the Venezuelan Foundation of the Center for Political and Social Studies.