Characters have been not studied in depth by the theories concerning transmediality, which are focused instead in the concept of world-building that belongs to transmedia storytelling (Jenkins 2006). The main theoretical issues around the central concept of transmedial character’s identity are exposed in this paper, while applied to the study of the television series Sherlock (BBC One 2010-). Finally, it is proposed to place transmedial characters, as the center of some transmedial narratives, at the same level of transmedial worlds.