Homelessness is frequently assumed to be a fixed state that suspends people in time and space as they enter into contexts and environments where they struggle to exert control over their lives and their futures. Furthermore, a multitude of negative identities are ascribed to people who are homeless based on their lack of stable housing. A growing literature has contributed to a more nuanced understanding of the identity "work" engaged in by youth who experience homelessness. Nonetheless, most studies have examined the construction of identity cross-sectionally; in many cases, exclusively or primarily through the lens of youths' experience of street and shelter life. Additionally, while the home has long since been argued to provide a secure base around which identities are constructed and ontological security attained, the intersection of identity with ontological security has, hitherto, not been adequately addressed within the youth homelessness literature. This paper examines the identity journeys of homeless young people based on selected findings from a six-year biographical longitudinal study of homeless youth in Dublin, Ireland. The analysis--which is organised according to the themes of "rupture," the "interruption of trust," and the "(re)assembling of self"--builds on existing studies by engaging with the concept of ontological security alongside an examination of young people's accounts of, and reflections on, their journeys through and, in some cases, out of homelessness. The paper concludes by discussing the importance of understanding the identity stories of homeless youth through longitudinal biographical narration and addresses the policy implications arising from the findings presented.