South Asia abounds with diverse gender identities that vary regionally based on religion, language, and cultural practices. Transgender rights activists have successfully deployed human rights rhetoric in order to obtain legal recognition of diverse gender identities from courts. However, the collapsing of these diverse identities and practices into a single category, under the transgender umbrella, by governments and judiciaries has created complex mechanisms for legal recognition of transgender persons. Simultaneously, international human rights principles are being invoked to win victories at the national level, which in turn offers insights into the dynamic interplay between law, activism, and human rights. In this article, we outline the constraints and opportunities presented by the changes in legal recognition of diverse gender identities across South Asia. We argue that the uses of international human rights statutes in national-level legal and judicial deliberations about recognizing transgender persons across South Asia offer limited opportunities, and mostly delimit access to formal citizenship, the very objective these laws seek to achieve. Simultaneously, this moment of wrestling with the limits of law, while continuing to demand full recognition from individual states, has given rise to cross-border mobilizations of a vibrant transgender rights movement. Such mobilizations reveal how diverse transgender activists are reinterpreting human rights principles in order to create coalitional multi-issue trans/justice movements throughout South Asia.