In today’s globalised world, the needs of English language learners have changed, particularly those learning to use the English language as a lingua franca. The growing research showcasing the global use of English as a Lingua Franca (ELF), the creativity of ELF users and the diverse ways in which they negotiate successful communication in multilingual encounters have numerous implications for the field of TESOL. This article reports on a study with pre- and in-service TESOL practitioners taking a Global Englishes for Language Teaching (GELT) option course in a one-year Master’s in TESOL programme at a Russell Group University in the UK to explore attitudes towards GELT, but also towards the proposals for, and barriers to, curriculum innovation discussed at the theoretical level, as well as factors influencing such attitudes. Interviews (n=21) and questionnaires (n=47) revealed that attitudes remain norm-bound, yet the study revealed a positive orientation towards GELT and provides insights into the feasibility of GELT-related curriculum innovation and teacher education syllabus design. The study calls for more research with pre- and inservice TESOL practitioners at different stages of the innovation process to ensure successful and sustainable GELT curricular innovation.