Globally, approximately 27.2 million children are working in the service industry. Due to the COVID-19 outbreak, it is estimated that an additional 8.9 million children will be pushed to work by the end of 2022. Children engaged in work are exposed to many physical and psychological risks, including being underpaid, working long hours, having limited access to education, experiencing sexual assault, and being trafficked for economic gains. Given these child labour issues, the United Nations has established #8.7 the elimination of child labour in the United Nations Sustainable Development Goals. Despite this goal, the number of child labourers has increased in the service industry. Three major challenges have impeded the eradication of child labour in tourism: (i) the subjectivity of the definition of child labour, (ii) the nature of tourism work, and (iii) the controversial antipode views on child labour. To overcome these challenges, this thesis spotlights the academic focus on child labour to host-children who are formally and informally engaged in tourism. The overarching aim of the thesis is to improve host-children's quality of life by listening to their lived experiences. This thesis is guided by four research objectives (ROs). They are:- RO 1: to identify the extent of knowledge and understanding of host-children in tourism; RO 2: to discuss the best way to conduct research with host-children by ethically mitigating the generational and colonial issues between a researcher and host-children; RO3: to understand host-children's lived experiences of tourism engagement from their perspectives, and RO 3.1: To understand how host-children perceive tourism impacts on their quality of life RO 3.2: To understand how host-children perceive their engagement in tourism RO 4: to explore the appropriate theoretical views on host-children's engagement in tourism to improve their quality of life. The research objectives are addressed through a transformative paradigm by listening to the voices of 94 Cambodian host- children (62 host-children within NGOs and 32 host-children on the street) through multi-mixed methods, including visual research methods (drawings and researcher-driven photo-elicitation interviews) and traditional qualitative methods. ... Overall, the empirical research in this thesis discovers that Cambodian host-children have both positive and negative experiences in their engagement in tourism because of their insider views as children and the sociocultural complexity of Cambodia. Hence, host-children's engagement in tourism is not a dichotomic black-or-white issue but a complicated social phenomenon. The findings of papers 3 and 4 raise a question about what an appropriate theoretical view on host-children's engagement in tourism is to improve their quality of life (RO 4). RO 4 is mainly achieved in paper 4 by proposing a transformative paradigm as a theoretical view while incorporating the core ideologies of universalism and cultural relativism. Paper 4 discusses how a transformative paradigm can be a theoretical view of empirical research on children's engagement in tourism. Underpinned by the transformative paradigm, this thesis argues that we need to establish a safe place for host-children by maximising their perceived benefits and minimising the costs of tourism engagement rather than the hasty eradication of child labour. This thesis offers theoretical, methodological, and practical contributions. Theoretically, it advances the tourism knowledge about host-children and child labour by exploring host-children's lived experiences and proposing a new theoretical view on host-children's engagement in tourism – one that bridges the dichotomy of universalism and cultural relativism. Methodologically, this thesis contributes to tourism research where host-children's voices are absent due to ethical and methodological challenges. This thesis demonstrates that visual research methods can mitigate the generational and colonial power gaps and successfully elicit the subconscious thoughts of children who have limited cognitive and linguistic capability. Practically, this thesis encourages collaboration between practitioners, including international organisations, governments and destinations, to work on improving host-children's quality of life by addressing their needs and wants and sociocultural complexities.