Ecological dominance is a central concept in the study of interspecies and species-environment relations. Yet, although theoretical and empirical work on ecological dominance has progressed in many scientific disciplines, the psychology of ecological dominance remains understudied. The present research attempts to advance theoretical and empirical inquiry on ecological dominance as a psychological entity, examining how and why it influences humans' perceptions, attitudes, and behaviors across different relational domains (i.e., intraspecies, interspecies, human environment). To this end, we introduce and validate a brief and novel measure, the Ecological Dominance Orientation (EDO) scale, based on the popular depiction of eco-centric vs. anthropocentric perspectives on the relationship between humans, non-human animals, and the natural environment. Across 3 studies conducted in 3 countries, we demonstrate that EDO (a) shapes perceptions in a similar fashion within and between different relational domains, b) is uniquely predictive of numerous socially consequential attitudes and behaviors across relational domains over and above established measures of discrimination, values, political ideology, and c) is reliable over time. This research extends classical Social Dominance Theory (Sidanius & Pratto, 1999) by theorizing about the evolutionary origins of intergroup, interspecies, and human-environment relations as hierarchically structured power relations. Theoretical and practical implications of social and ecological dominance orientations are discussed.