Well-being is, according to relevant research, considered to be an important resource for positive development and a driver for successful (lifelong) learning. Well-being is understood both as an outcome in terms of positive mood and life satisfaction, as well as a process of personal development. In our research projects, we particularly address questions about school well-being and its relevance for educational success. In close cooperation with interested schools, we examine relations with motivation, performance, school and class climate as well as possibilities of promoting well-being in school.