Tourist guides are at the frontline of sustainable tourism. Through their daily interactions with visitors, they translate global values into lived experience and shape how heritage is understood, respected and transmitted. This keynote situates the work of tourist guides within UNESCO’s normative frameworks, highlighting how these instruments can support value-based heritage interpretation in the face of overtourism, climate change and economic pressures. Drawing on the World Heritage Convention (1972), the Convention for the Safeguarding of the Intangible Cultural Heritage (2003), and the Convention on the Diversity of Cultural Expressions (2005), the address underscores a shared principle: heritage is living, dynamic and rooted in communities. UNESCO’s policy mechanisms—such as sustainable tourism strategies for World Heritage properties, community-based safeguarding approaches, and the integration of culture within the 2030 Agenda—offer practical reference points for guiding practices grounded in respect, authenticity and inclusion. As the World Federation of Tourist Guide Associations finalizes its new Code of Guiding Practice aligned with the Sustainable Development Goals, this keynote affirms tourist guides as essential cultural mediators. By aligning professional ethics with UNESCO’s normative instruments, guides can strengthen the sustainability of their profession while contributing to more responsible, people-centred and future-oriented tourism.