Youth mobility and well-being: transitions and intersections LulleAija KingRussell 2019 This introductory paper, reflecting the rubric of the special issue, brings together two themes that have recently become prominent in migration research: a focus on youth mobilities, and a concern to analyse the process and outcomes of migration through a well-being lens. The five papers that follow approach this intersection in a variety of European contexts and from a plurality of theoretical, methodological and thematic angles. The special issue is a product of the Horizon 2020 YMOBILITY research project on ‘New European Youth Mobilities’, which ran from 2015 to 2018, and most of the papers were first presented at a dedicated session on Youth Mobility and Well-being at the IMISCOE Annual Conference in Rotterdam, 28–30 June 2017.1 The purpose of this editors’ introduction is to ‘map the fields’, which we do by organising our presentation in the following way. In the next section, we open up a discussion on the nature and diversity of youth mobility, looking, in particular, at the way in which young people’s international mobility interfaces with their youth transitions to ‘adulthood’. Then, we review the well-being approach to migration and mobility, with special reference to youth mobilities. The final section of the paper summarises key findings from the five papers that follow.