AbstractDepictions of sadness are commonplace, and here we aimed to discover and catalogue the complex and nuanced ways that people interpret sad facial expressions. We used a rigorous qualitative methodology to build a thematic framework from 3,243 open-ended responses from 41 people who participated in 2020 and described what they thought sad expressors in 80 images were thinking, feeling, and/or intending to do. Face images were sourced from a novel set of naturalistic expressions (ANU Real Facial Expression Database), as well as a traditional posed expression database (Radboud Faces Database). The resultant framework revealed clear themes around the expressors’ thoughts (e.g., acceptance, contemplation, disbelief), social needs (e.g., social support or withdrawal), social behaviours/intentions (e.g., mock or manipulate), and the precipitating events (e.g., social or romantic conflict). Expressions that were perceived as genuine were more frequently described as thinking deeply, reflecting, or feeling regretful, whereas those perceived as posed were more frequently described as exaggerated, overamplified, or dramatised. Overall, findings highlight that facial expressions — even with high levels of consensus about the emotion category they belong to — are interpreted in nuanced and complex ways that emphasise their role as other-oriented social tools, and convey semantically related emotion categories that share smooth gradients with one another. Our novel thematic framework also provides an important foundation for future work aimed at understanding variation in the social functions of sadness, including exploring potential differences in interpretations across cultural settings.