Immigrants increasingly engage in homeland-oriented transnational institutional and non-institutional collective political action. Immigrant transnational political action, in turn, is largely conceptualised as being determined by either contexts of reception in receiving societies or diaspora policies emanating from immigrant origin countries. Thus, existing literature largely views immigrants’ transnational political action as a product of one particular political context or policy, which neglects to account for the ways in which their transnational politics are simultaneously embedded in and shaped by multiple political contexts. In this paper, we develop a nuanced account of the distinctive ways in which multiple political contexts shape the cross-border electoral, organisational and non-institutional collective action of immigrants and diaspora communities. By doing so, we transcend analytical emphases on receiving-society effects which largely view homeland-oriented politics through the lens of immigrant incorporation. We propose a triadic political opportunity approach to conceptualise how varied receiving-country, origin-country, and transnational political contexts shape immigrant transnational political action. We illustrate the utility of this approach by drawing on original research and secondary sources to demonstrate how receiving, origin and transnational political opportunity structures can facilitate and/or constrain immigrant transnational political action. We conclude with a discussion of potential applications of our approach for future research.