Loneliness, often referred to as the 'epidemic of the 21st century', has emerged as a grave public health concern. For years, a lack of comprehensive European cross-national data hindered a thorough examination of this issue. In 2022, the European Commission's Joint Research Centre conducted the inaugural EU Loneliness Survey, covering around 30,000 individuals in 27 European nations. The book sheds light on who is most affected by loneliness, identifies contributing experiences and behaviours, addresses the stigmatisation of loneliness and discusses its societal impact. Furthermore, it emphasises the importance of interventions to combat loneliness. Finally, the book discusses the challenges of survey design and offers valuable insights for the monitoring of loneliness in Europe in the future. This makes the book a must-read for scholars and academics interested in population economics, public health and social well-being.