This article provides evidence-based results regarding current debates on transnationalism. It draws on the content analysis of the 50 most cited (according to the major academic databases and search engines in 2020) and the 50 most recent (published or forthcoming in 2019–2020) articles and/or books on transnationalism. The study analysed the main definitions of transnationalism, identified classification criteria for transnational experience, and reviewed the concept of transnationalism in the studied articles and books. In transnationalism, a broad range of economic, sociocultural, and political cross-border activities and practices, and their various combinations, modify people’s sense of belonging to places; affect their citizenship and nationality; change their aspirations, imagination and decisions in everyday life; and influence their identity. In the studied academic literature, transnationalism was often associated with globalisation, migration, cosmopolitanism, multiculturalism, diaspora, post-migration studies, and internationalism. Transnationalism has an inner processual and in-becoming character, leading to difficulty in giving it a precise and clear theoretical definition. Many studies have shown the need for conceptual academic clarity regarding transnationalism, whether considering it from narrow or broad perspectives. Transnationalism is transformative, and powerful enough to trigger changes in contemporary societies. This article suggests a number of particularly intriguing research fields regarding transnationalism: telecommunications (ICT—Information and Communication Technology/the internet/social media), return migration (aspirations to return, and in relation to telecommunications), as well as the connection between bodies and the law (the incorporation of the body into transnational practices and in relation to the law).