The relationship between nations (or states), languages and social cohesion have been studied over time. Contexts like Africa and India challenge the conceived Western notion of "one-nation-one-language". Insights about multilingualism and social cohesion from complex sociolinguistic contexts like South Africa could provide a deeper understanding helpful for promoting social cohesion in emerging "super-diverse" situations across the globe. This article reports on selected data from a longitudinal language repertoire survey conducted over three periods (1998, 2010 and 2015) in the Vaal Triangle region in South Africa. It discusses the views of multilingual urban students (N=1900+) about the relationship between multilingualism and social cohesion. The main findings are that the multilingual African home language participants believe that being multilingual is related to social cohesion, while this is not a prominent finding for Afrikaans home language users (who are mainly bilingual). The data from the South African context indicate the importance of multilingual repertoires as instruments that support the fostering of social cohesion in complex settings. Multilingual repertoires facilitate communication that enhances the building of better relationships and a deeper understanding between people in diverse settings. The implications of the findings for emerging "super-diverse" global societies are discussed.