Becoming a teacher involves not merely the accumulation of disciplinary knowledge and pedagogical techniques, but also significant transformations of identity. A sensitive and research-based appreciation of the nature of these transformations, and their significance for beginning teachers, is potentially valuable for both pre-service teacher education and early-career teacher support practices. Drawing from a recent empirical study this article examines liminality, or paradoxical in-betweenness, as an inherent, and inherently difficult, experiential quality of becoming a teacher. Analysis of four individual case studies of beginning teachers reveals three concrete manifestations of liminality: 'being-a-stranger'; 'being-a-fraud'; and 'dancing in the disequilibrium'. The findings show how these unstable, in-between spaces of identity-making present complex challenges, but also constitute sites of agency and productive identity-work, for beginning teachers. The discussion provokes questions regarding how teacher educators and school administrators can account for, and respond to, liminality.