This special issue brings together scholars from a range of disciplines and contexts concerned with children, 1 childhood and bilingualism; that is the ability to communicate in two or more languages with any degree of proficiency, from minimal to advanced (Grosjean, 2010). Language is fundamental to human culture and personhood and a key part of identity at an individual, family and community level. However, language may also be used at a national level as a tool for building nationhood and empire in ways that create power hierarchies. State-sponsored language polices have often marginalised minority languages, whether these are long-established and termed indigenous to the area 2 or associated with more recent migration. Equally, bilingualism may be undermined in settings built on monolingualism. As seen in this special issue, national education policies in some countries now offer more support to minoritised indigenous languages but have been slower to recognise the linguistic resource offered by more recent migrant or ethnic language communities, whose languages are still too often treated as an impediment to educational achievement and social integration (Pavlenko & Blackledge, 2004).Research points to important advantages of bilingualism in child development and education. Cognitive science research shows the benefits of early bilingualism on language and cognition, including children's better understanding of language structure, an earlier appreciation of others' perspectives and enhanced attentional control and mental adaptability (Bialystok et al., 2009;Costa & Sebastian-Galles, 2014;Kroll & Bialystok, 2013). Language-awareness approaches in education highlight the value of linguistic diversity in developing metalinguistic skills and in preparing children for a globalised, multilingual and multicultural world (Hawkins, 1984;Hélot et al., 2018). Therefore, bilingualism, can be both individually and collectively advantageous.However, research to date has insufficiently attended to the experiences and perspectives of children themselves, which limits, in turn, the understanding of bilingualism (Peace-Hughes et al., 2021;Wilson, 2020). The perspective of childhood studies that highlights children's participation in the construction of their day-to-day lives and the world around them (James & Prout, 1997;Spyrou, 2018), offers one route to insightful and nuanced understandings. In this special issue, authors use different lenses and framings to examine the ways in which languages and childhoods articulate and are implicated in children's senses of self, ways of seeing and feeling, imagined solidarity, local-national-and-transnational belonging, agency and aspirations.The collection contributes to theorising intersectional power dynamics between children, young people and adults. The theme is foregrounded in the discussion of children as language brokers and translators for parents/carers