This chapter explores the themes of acculturation and identity transformation among seven Chinese language teachers in Hong Kong. These teachers, who initially taught Chinese as a first language in local Chinese schools, later transitioned to teaching Chinese as a second or near-native language in English-dominant international schools. This study utilises a qualitative research approach, focusing on the long-term teaching experiences of the participants to gain insights into their transformational experiences and acculturation processes from their narratives. We draw on flexible acculturation theory and teacher identity theory to examine the connections and disconnections between acculturation processes and identity change across schools. The findings underscore the participants’ profound meaning-making processes as they trainsitioned from teaching in local schools to international schools. The participants’ previous professional identities as L1 teachers allowed them to draw on multiple resources with a deeper understanding about language teaching and and self-assurance in their changing roles as language educators. They critically reflected on these changing experiences in their subsequent teaching practices within international school contexts. This study holds implications for teacher education and professional development programmes, suggesting the need for tailored initiatives designed to support Chinese language teachers during their transition to teaching in international schools. Copyright © 2023 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.