We investigate macrocontextual antecedents of national levels of Social Dominance Orientation (SDO). The majority of previous research, in contrast, has tended to focus on individual-level correlates of SDO. We extend research on Social Dominance Theory by modelling national-level differences in institutional discrimination, macroeconomic development, and value ideologies as broad situational factors affecting SDO mean levels in previous studies. Our hypotheses were tested in a three-level meta-analysis of aggregate data from 50,971 individuals in 95 samples from 27 different societies. Strong effects for hierarchy-attenuating legitimizing ideologies and gender empowerment were found. Aggregate discrimination against arbitrary-set groups was less consistently linked to SDO, suggesting that these hierarchies are context-specific. Using mixed-effects three-level modelling, the patterns can be generalized to new contexts and suggest a particular institutional and social climate that fosters high SDO.