White supremacy is a system of domination that historically and transnationally shapes social, epistemic, political, and subjective arrangements, grounded in the centrality of white raciality as the normative standard of humanity, rationality, and value. Beyond extremist ideologies, it operates in a capillary, naturalized, and deeply rooted way within institutions and in the very formation of subjects. This entry examines the multiple dimensions in which white supremacy manifests itself—economic, political, historical, and identity-related—highlighting its impact on the constitution of subjectivities, including in the field of psychology. It further analyzes how white supremacy sustains a racialized ontology of existence and confronts the universalist claims of psychological science. Finally, it presents critiques, tensions, and theoretical-practical pathways for dismantling this regime of power, drawing on critical and antiracist epistemologies that challenge the epistemic hegemony of white supremacy.