This book contributes an analysis of UK-based non-governmental organisations engaged in transnational lesbian, gay, bisexual, and trans (LGBT) activism, within a broader recognition of the complexities that British colonial legacies perpetuate in contemporary international relations. From this analysis, the book suggests that greater engagement with intersectional and decolonial approaches to transnational activism would allow for a more transformative solidarity that challenges the broader impacts of coloniality on LGBT people's lives globally. Case studies are used to explore UK actors' participation in the complexities of contemporary transnational LGBT activism, including activist responses to developments in Brunei between 2014 and 2019, and the use of LGBT aid conditionality by Western governments. Activist engagements with legacies of British colonialism are also explored, including a focus on 'sodomy laws' and the Commonwealth, as well as the challenges faced by LGBT people seeking asylum in the UK.