As Pennington and Richards (2016) observe, a teacher's sense of what it means to be a teacher is created interactively with the knowledge base and identity of the larger field. Technological developments and unprecedented societal change have recently, however, rendered the?teaching profession more complex and diverse. This is particularly evident in higher education settings, where clear divisions between professional and academic areas are increasingly blurred. The breaking down of strict boundaries between professional domains gives rise to a "third space" (Whitchurch, 2008), which staff, including language teachers, must learn to navigate. Reconstructing their identities in highly dynamic third spaces can place language teachers in liminal states of inbetween-ness and ambiguity (Beech, 2011), where negotiating stable identities becomes especially demanding. While language teacher identity in the context of higher education has been widely discussed, the implications of transitioning into 'third space' settings for language teachers' identities have received less attention. Adopting a "theorising from practice" approach (Richards, 2016), in this reflective autoethnographic article, we examine our shifting language teacher identities as we seek to successfully navigate 'third space' work environments in New Zealand and Switzerland. We use critical reflection to explore how our professional identities have evolved as we switched from relatively 'bounded' language teaching roles to more fluid and dynamic 'third space' positions. Further, we discuss the role of professional development as enablers (or inhibitors) of our evolving language teacher identities as we moved into roles that diverged from what we had initially trained for. Lastly, we relate these reflections to suggestions for professional development that could help language teachers better respond to the demands of an increasingly diversified and complex profession.