The increasing need for innovative research driven by rapid global changes gives doctoral supervisors of early-stage researchers a significant role in facilitating the ethical conduct of qualitative research. In the context of European Commission funding, the demands of research ethics and integrity place a tremendous responsibility on the supervisors of early-stage researchers involved in cross-national projects. This document study seeks to illuminate the role of the supervisors in facilitating research ethics in these projects. Specifically, we describe and discuss the supervisor role associated with five approaches to doctoral supervision of qualitative research, namely those described as 'Functional', 'Enculturation', 'Critical thinking', 'Emancipation' and 'Developing a quality relationship'. The main challenges for supervisors of cross-national research projects are the cultural and linguistic mobilisation of ethical principles in qualitative research processes and the management of the future use of open data. The results from this study have implications for planning and conducting cross-national studies within research involving human participants. These results can guide supervisors in the codification and mobilisation of ethical qualitative research in practice.