Corporate social responsibility (CSR) towards the notions of diversity, equality, and inclusion (DE&I) draws a lot of attention in modern, pluralist society. The organizations’ communicative approach in conveying LGBTQ advocacy to manage tensions and avoid conflicts with various stakeholders is largely underexplored in the Asian context. This study adopts Carbaugh’s cultural discourse analysis (CuDA) to examine the socio-cultural meanings of LGBTQ-supportive CSR discourse for building corporate legitimacy in Hong Kong. CSR materials from leading corporations (2016–2022) and Facebook comments from the public were selected. We analyzed the CSR discourse using the five discursive hubs of CuDA (i.e. identity, emotions, actions, relations, and dwelling) and Suchman’s legitimacy theory (i.e. pragmatic, cognitive, and moral). Our findings revealed three different stages of corporate legitimacy: namely, symbolic, institutional, and contextualized LGBTQ advocacy. The CSR materials intertwining in the five discursive hubs also demonstrated how the organizations attempted to build corporate legitimacy by fostering social change and avoiding conflicts through positive and implicit message-framing of LGBTQ advocacy. Discourse reflected in these CSR strategies illuminated the importance of glocalizing CSR messages to facilitate stakeholder engagement and corporate legitimization in support of this controversially progressive value.