Loneliness and social isolation are increasingly being recognised as public health challenges. This report aims to present loneliness, social isolation and social connection in Wales from a public health perspective. Intended for professionals, policymakers and other individuals working directly or indirectly in the field of social connection, it includes data and evidence on: the prevalence of loneliness, social isolation and social connection in Wales and the population groups most affected; factors that increase the risk of loneliness and social isolation; impacts on health and well-being; evidence on solutions; examples of good practice in Wales; and key areas for future action.