Math anxiety and personality influence numeracy, although the nature of their contribution has been overlooked. In the present study, we investigated whether their association with numeracy depended on field of study and gender in higher education. Participants were Italian undergraduates in either the humanities ( N = 201) or Science, Technology, Engineering and Math (STEM; N = 209) fields of study. These participants remotely completed standardized tests assessing numeracy, math anxiety, personality, intelligence, and basic numerical skills. We tested whether math anxiety and personality interacted with field of study and gender in predicting numeracy. Results showed that math anxiety was negatively associated with numeracy independently of field of study and gender, while the effect of personality, especially neuroticism, on numeracy interacted with field of study over and above intelligence and basic numerical skills. Specifically, humanities undergraduates with higher neuroticism levels scored lower in numeracy than STEM undergraduates. These findings underscore the importance of emotional experience for a good performance in mathematics, beyond math anxiety and the other personality traits, in the students that are less familiar with mathematics. Finally, no robust gender moderation emerged, suggesting that its role may be overridden by differences associated with career choice.