This study looks at the Australian Timorese diaspora to answer the question: what roles did the diaspora play in conflict transformation processes in Timor-Leste? Participants in the research include Timorese Australians who had left before 1998 and returned to Timor-Leste; Timorese scholarship students who studied at Australian universities, since they most likely had contact with Timorese Australian communities, and development workers who have worked in Timor-Leste. There is an increasing interest in diaspora and their roles in peacebuilding in their home countries. This thesis aims to contribute to this field of research by describing lessons learnt after 20 years of independence in Timor-Leste. Furthermore, this thesis provides an analysis of diasporas’ roles in peacebuilding and development, noting their ability to move between insider and outsider roles. Interview data were analysed along three key themes: diaspora returning to Timor-Leste; perceptions of diaspora Timorese, and nation building. Using indigenous and autoethnographic methodologies, together with reflexive thematic analysis, it was found that Timorese diaspora and student participants have a strong sense of cultural identity, experiences of resistance and resilience, and feeling of belonging to the Timorese nation-state. Many factors created divisions between returning diaspora and the local Timorese. These include peacebuilding programs led by international organisations, changes in working languages, trauma, and political conflicts. By building connections, grass-roots Timorese, Timorese diaspora, returned Timorese students, development workers, and stakeholders can collaborate on the development of Timor-Leste