Gender, racial/ethnic, and socioeconomic disparities pervade academia. Though there are a wealth of established reasons for these gaps, recent research has begun to examine how faculty beliefs contribute to representation outcomes for groups stereotyped as lacking intelligence. Extending prior research and using a sequential explanatory mixed methods approach, the present study investigates how field-specific ability beliefs (beliefs about the importance of brilliance) and fixed mindsets (beliefs about the immutability of intelligence) relate to the representation of women, racial/ethnic minorities, and first-generation students at various levels of academia. In a quantitative study of 1,025 faculty from 83 departments, self-reported beliefs exhibited negative correlations with representation outcomes in the small to very large range (−.16 > r’s > -0.44). Qualitative findings, however, suggest a more complicated relationship. Focus group data from undergraduate and graduate students in two departments differing in faculty beliefs (N = 32), suggested that both explicit and implicit messages from professors, peers, and the learning environment are important contributors to students’ experiences, beliefs, and decisions. The results call for more intentional considerations, both in research and in practice, of the messages students receive from the environments in which they learn.