Based on 20 in-depth interviews with young Spaniards aged 20–35 years in the London region, this article explores the linked processes of migration, adaptation, and young–adult life transitions from the perspective of psychosocial well-being. Although most young Spaniards have moved for economic reasons, they also have personal and emotional motivations. The article explores factors that mediated their well-being experiences in the destination setting, such as the role of social networks and the achievement of their aspirations. Aspirations were not only material, in the form of a steady and higher income, but also factors such as language improvement, reuniting with a partner or friend, and being independent from their family. The findings of the paper contribute new insights into the factors that condition the relationship between migration and psychosocial well-being during the transition of young people to adulthood.