This paper considers issues around identity for teaching assistants (TAs) in mainstream English primary schools. We discuss the concomitant problems TAs experience around role definition and role-creep as well as the challenges inherent in equivocally defining their evolving and flexible role. We used key themes drawn from the literature considered to suggest that professional identity is broadly socially, relationally and contextually dependent, changeable and multifaceted. We then explore how these terms relate to the work and roles TAs undertake in school. The paper concludes with recommendations for schools to support the development of a contextually relevant identity for TAs so the flexibility in their role can be advantageous for TAs, teachers and children.