Recent research has documented the rapid growth in the number of universities offering degree courses using English as the medium of instruction (EMI) throughout Asia. While some of this research has considered the impact of EMI instruction on student learning, only limited attention has been given to the experiences of other stakeholders, such as academic staff who are expected to deliver EMI courses in tertiary institutions. Therefore, this chapter explores the perspectives and experiences of academic staff at a large EMI tertiary institution in Hong Kong. Using a framework of teacher identity, the chapter considers the role of EMI policy and practice in the ability of academic staff to negotiate multiple identities, including ‘academic economist’, ‘researcher’, and ‘teacher’, by revealing the dominant discourses that constrained and enabled their professional identity construction. The data describes the challenges that academic staff experience in constructing their preferred identities in an EMI environment and how they negotiated such challenges. Implications for policymakers wishing to support the identity construction of academic staff at EMI tertiary institutions throughout Asia and beyond are considered and suggestions for future research discussed.