Actors in the classical world were often viewed as frauds and impostors, capable of deliberately fabricating their identities. Conversely, they were sometimes viewed as possessed by the characters that they played, or as merely playing themselves onstage. Numerous sources reveal an uneasy fascination with actors and acting, from the writings of elite intellectuals (philosophers, orators, biographers, historians) to the abundant theatrical anecdotes that can be read as a body of "popular performance theory." This study examines these sources, along with dramatic texts and addresses the issue of impersonation, from the late fifth century BCE to the early Roman Empire.