With rates of vegetarianism and veganism (i.e., veg*nism) rising around the world, a growing body of research has begun to explore psychological characteristics that distinguish vegetarians and vegans from omnivores. However, relatively few studies have examined how veg*nism is related to differences in basic personality traits such as the “Big Five”, with those that have tending to yield conflicting results. Moreover, none of these studies have examined personality at the lower levels of the personality trait hierarchy (i.e., aspects and facets of the Big Five). Thus, we sought to clarify how personality traits are related to veg*nism. In Study 1, comprising two samples (S1a: N = 797, S1b: N = 1534), participants were categorised as Veg*n vs Restricted-omnivore vs Omnivore, and completed personality questionnaires at the domain and aspect levels of the Big Five. In Study 2, participants (N = 562) completed both categorical and continuous measures of veg*nism, along with personality questionnaires at the domain, aspect, and facet levels. Across both studies, we found that people who scored higher on traits within the openness/intellect and agreeableness domains most consistently reported higher levels of veg*nism. Patterns in the data also suggested that the relation between personality and veg*nism might depend on the way veg*nism is measured. Theoretical and practical implications of these findings are discussed.