Mental Health and Well-Being Among Students in the European Union. The present study is the first attempt to estimate the prevalence of mental health problems among students in Europe by analyzing survey data from the Organization for Economic Co-operation and Development and its member states. Mental health problems, academic performance, suicidality, and perceived level of happiness were used as key indicators of mental health problems. Data were collected in the school years 2010/2011 and 2011/2012 from students aged 15 and 16 years (N = 718,700), from 33 countries in the European Union, and were analyzed cross-sectionally. Findings revealed that 1.6 to 4.1% of the students were estimated to have a mental health problem, with girls being at higher risk than boys. The highest prevalence of mental health problems was reported for the Czech Republic (7.6%) and the lowest for Austria (1.3%). Furthermore, students in vocational education and training had more mental health problems than those in general/academic education. The same was found for students with chronic disease, non-German-speaking background, and those with low socioeconomic status. The most prevalent mental health problems in students were depression and psychological distress, whereas anxiety problems were rare. About 2.1% of students had suicidal thoughts, and 1.1% made suicidal plans or attempts. The study adds information about the mental health of students in Europe. The findings should encourage governments to increase spending on student mental health programs. Also, there is a need for more research on the effectiveness of such programs. (PsycINFO Database Record