Objective: Weight stigma is prevalent across multiple life domains, and negatively affects both psychological and physical health. Yet, research into weight stigma reduction techniques is limited, and rarely results in reduced antipathy toward higher-weight individuals. The current pre-registered study investigated a novel weight stigma reduction intervention. We tested whether a writing exercise focusing on body functionality (i.e., everything the body can do, rather than how it looks) of another person leads to reductions in weight stigma. Method: Participants were 98 women (Mage = 23.17, Range = 16–63) who viewed a photograph of a higher-weight woman, “Anne,” and were randomised to complete a writing exercise either describing what “Anne’s” body could do (experimental group) or describing her home (active control group). Facets of weight stigma were assessed at pretest and posttest. Results: At posttest, the experimental group evidenced higher fat acceptance and social closeness to “Anne” compared with the active control group. However, no group differences were found in attribution complexity, responsibility, and likeability of “Anne”. Conclusions: A brief body functionality intervention effectively reduced some, but not all, facets of weight stigma in women. This study provides evidence that functionality-focused interventions may hold promise as a means to reduce weight stigma.