Since the 1970s, schools in Ireland have offered an optional programme known as 'Transition Year' midway through secondary education, when students are typically 15 years old. It lasts one academic year and aims to promote maturity, social development and vocational exploration, and to give students a chance to develop personal and intellectual interests in the absence of high-stakes examination pressure. On returning to more conventional classes, participants are expected to be better prepared to study and better prepared for life beyond school. The evolution of Transition Year over nearly half a century has been driven primarily by committed teachers and particular policy decisions, but, despite increasing uptake, it has lacked a strong theoretical grounding. This has contributed to a measure of public ambivalence and vulnerability to political vicissitudes. This paper reviews the extant literature on Transition Year, situates Transition Year in the context of selected aspects of the psychological literature on socioemotional development, highlights avenues for future research and discusses its relevance to social and emotional learning in global education beyond Ireland.