High school dropouts are likely to experience challenges during the transition to adulthood, notably in terms of employment. For them, jobs are often hard to find, low-paid, and unstable. Many dropouts thus re-enroll in school, and some go on to obtain a high school or vocational diploma or even a college degree. However, others do not re-enroll or abandon school again, while some disengage from both education and employment. In other words, high school dropouts experience heterogeneous pathways during their transition to adulthood. A small but growing body of research attempt to document these pathways and their antecedents and consequences, as well as effective programs and services to reconnect those at risk of marginalization. This chapter provides a broad overview of this literature, focusing on the transition to adulthood among high school dropouts in Canada, the United States, and Europe. In closing, key policies and practical implications are discussed.