This introductory chapter argues that Southeast Asia, a region whose boundaries are delimited more by politics than by other markers, is a conceptually meaningful site for interrogating the paradigm of transnationalism. The transnational paradigm is defined as a spatial area model that operates from the outer perimeters to study the way that the transnational has been deployed in various disciplines to examine historical connections and contemporary interactions across borders. This chapter suggests that transnationalism remains relevant for analysing cultural flows predicated on historical connections, but not without modifications or nuanced applications. By deploying the transnational paradigm as an operative framework, the introduction highlights various social networks at work, illuminated by the prevailing typologies of transnationalism. The volume is divided into three broad themes to underscore communities, contestations and cultures in Southeast Asia. The first section examines migrant and diasporic communities, their experiences of assimilating into host societies and their lingering connections with cultural homelands. The second section explores the construction and representation of identities by institutions and cultural others in novels, newspapers and literary writings, considering how such identities are contested by individuals and institutions. The third section evaluates the practice and production of culture, encapsulated in artefacts and literary discourses. Ultimately, the volume discusses adaptations of the transnational paradigm in Southeast Asia, breaking new ground with its transdisciplinary approach and dialogic criticism to interrogate the transnational paradigm.