Identity development is a critical psychosocial task with relevance across the life span, but which plays a central role in adolescence and emerging adulthood. Broadly, identity development involves constructing an understanding of who one is and how one came to be that person; that is, identity is an understanding of self that is integrated and coherent across time and context. Successful management of this developmental task facilitates psychological health, the ability to connect with others, and the ability to contribute to one’s society. This entry reviews two main approaches to identity development, describes identity development across different developmental stages, and considers identity development in the context of different social roles.