Society has undergone rapid changes over the last decade affecting adolescents and their mental health as well as experiences of loneliness. The aim of this study is to examine loneliness from adolescents’ and young adults’ perspectives. Data was collected through semi-structured interviews with eleven (n = 11) Finnish adolescents and young adults aged 17–28 and analyzed using qualitative content analysis. Two main themes and six subthemes were found. The main themes were: risk factors for loneliness and different ways of alleviating loneliness. Risk factors for involuntary loneliness were: social transitions, isolation, not having anyone to contact, group differences, social expectations, viewing other companionships, ill-being, negative emotions, former destructive experiences or a negative self-image. Preventive measures, effective coping strategies together with tertiary measures are depicted and discussed. Risk factors should be identified in order to be able to effectively and adequately address involuntary loneliness amongst adolescents and young adults.