Drawing on a review of recent international literature, this article argues for the first time that an understanding of, and engagement with, the theory and practice of friendship is essential to working alongside those who have care experience. Drawing on theory from philosophy, psychology and sociology, the care system is explored as a unique and challenging context for making and keeping the reciprocal, caring friendships which research suggests are important for a ‘happy, healthy life’. Our analysis shows how theories of friendship have failed to consider the friendship experiences of those in the care system. We suggest that including these experiences offers new opportunities to develop theory and practice in the field of friendship. We argue that friendship is an essential human need and, as such, should be placed centrally in assessment and intervention work, encouraging social workers to support positive and enduring friendships for the people they work with.