Acculturation refers to the process of change that arises from sustained intercultural contact between cultural groups and their individual members. Although these changes can occur at the group level, this article focuses on the changes that individuals experience as they negotiate recurring intercultural encounters over time; their pathways to positive development; and their psychological, sociocultural, and intercultural adaptation. Berry’s (1980) acculturation framework is the foundation of current theory and research. It identifies two dimensions, cultural maintenance and intergroup contact, as the defining features of acculturation attitudes and describes how these factors combine in different ways to result in one of four acculturation strategies: integration, assimilation, separation, and marginalisation. Over time Berry’s bidimensional model of acculturation has been broadened and reframed in terms of orientations to heritage and contact cultures, and has been extended to include not only attitudes, but also identities, values, and behaviours. Moreover, increasing emphasis has been placed on contextual factors and the interplay between the acculturation expectations held by majority group members and the preferences of acculturating minorities as highlighted in the Interactive Acculturation Model and Concordance Model of Acculturation. More recently, globalisation has created new experiences of acculturation that transcend national boundaries. The article describes the challenges posed by transnationalism, superdiversity, cosmopolitanism, and remote acculturation, and the subsequent emergence of tri-dimensional and polycultural models of acculturation. It also focuses on the implications of acculturation theory and research in everyday life, particularly in community, educational, and organisational settings.