Migration of unaccompanied immigrant and refugee youth has increased around the world in the last decade, peaking in 2014 in the United States and in 2015 in Europe. Youth are pushed to migrate without parents or guardians to escape war, persecution, gang violence, and extreme poverty in their country of origin. Youth are vulnerable to violence and abuse at the hands of smugglers during their journeys but show great courage and strength as they embark on their journey to a better life. The goal of this literature review is to provide a synthesis of empirical literature concerning this population. Thirty-one studies were included: 13 used qualitative methods, 13 quantitative, four mixed methods, and one used participatory methods. This body of research documents the stages of youths' immigration journeys from the decision to leave, to the migration process, to arriving in the new country and the resettlement experience. The migration journey was the overarching model in this review, and it describes the youth's complete journey, which continues after resettlement. We describe the four stages in the migration process identified in the experience of unaccompanied youth and their journey in this review: making the decision to migrate the experience during migration; psychological distress and coping upon arrival; and adaptation, acculturation upon arrival in the resettlement country, and impact of social support and social networks in the resettlement country. We end by offering recommendations for future research and immigration policy based on what is known and not yet known about the experiences of these courageous young people. (PsycInfo Database Record (c) 2022 APA, all rights reserved).