The Health Behaviour in School-aged Children (HBSC) study has been seeking to understand and monitor young people’s health across Europe and North America for more than 30 years. As the study has grown to include 50 member countries and regions, the utility of the data it provides for the well-being of 11-, 13- and 15-year-olds has also grown. This seventh international report in the series presents findings on adolescent health and well-being from 45 participating countries and regions in 2017/2018. It is divided into two volumes. Volume 1 provides an overview of the key findings highlighting important gender and socioeconomic differences, as well as changes since the last survey in 2013/2014. The key data are presented in Volume 2 in a series of charts showing country/region-level and overall prevalence by age, gender and family affluence.