The origins and development of the psychology of liberation are described, detailing the intellectual and political context in which the concept of liberation emerged in Latin American social sciences. Its constitution as a mode of doing psychology, and the founding ideas of Ignacio Martin Baró, its pioneer, are analyzed. Primary concepts such as problematization, de-ideologization, and de-alienation are discussed, and I explain how they are integrated into a central process characterized as conscientization. The role of relatedness as an epistemological base for knowledge construction and liberation is highlighted. The dynamics in which these processes interact in order to facilitate and catalyze the transformation of negative living conditions through participatory action and reflection, to empower people so they become conscious citizens, and to strengthening civil society and democracy is also discussed. I argue that the ethical, critical, and political character of the liberating actions respond for the participatory, reflexive, and transformative conception of this form of psychology.