This editorial introduces a broad Collection of works highlighting the central role of faces, the richest and most complex of social stimuli, in human behaviour. The Collection covers work from various areas of psychology, psychiatry, and neuroscience on different aspects of face perception: The development of face perception, the underlying cognitive and neural mechanisms of face perception, the role of faces in social interaction, how neurological or psychiatric conditions can affect face perception, as well as face perception in human–machine interactions involving artificial agents with face-like features. This body of work underscores the profound impact of faces on social interaction, aiming to promote dialogue among different disciplines and inspire future research in this vibrant research domain.