In a variety of personal and professional domains, heavy individuals face stigma associated with their body size. Here we investigate a new method for subtle detection of the negative perceptions consistent with that stigma. In two studies, participants were asked to view images of heavy and thin individuals while smelling substances that, unbeknownst to them, were odorless. Across both studies, the results showed that the substances were perceived to smell worse when they were paired with images of heavy individuals than when they were paired with images of thin individuals. These findings suggest that perceptions of stigmatized individuals can be assessed indirectly through olfactory responses. More generally, they suggest that the effects of weight stigma are broader than previously recognized.