Adolescents with a visible difference to the face or body (e.g., due to a congenital condition, illness, or injury), may be at risk of elevated psychological distress. Young Person’s Face IT (YPF), a web-based psychosocial intervention, has displayed effectiveness, but no previous study has specifically evaluated its cost-effectiveness. The aim of our study was to investigate whether YPF could be a cost-effective alternative for psychosocial support to adolescents distressed by a visible difference, relative to care-as-usual (CAU). Within the context of a randomized controlled trial in Norway, 102 participants (43% boys) were allocated to intervention (n = 55) or waiting list control group (n = 47). Mean age was 13.9 years (SD = 1.71; range 11–18), and all self-identified as experiencing distress related to a visible difference. Participants answered questionnaires including measures of health-related quality of life and social anxiety at baseline and 3-month follow-up. A health economic evaluation using the method of cost-utility analysis was performed, including quality-adjusted life-years (QALYs). Results indicated that the incremental cost-effectiveness of YPF was 63,641 Norwegian kroner per QALYs gained, which is well within the acceptability threshold in the Norwegian healthcare sector. Hence, YPF could potentially be considered a cost-effective intervention for adolescents experiencing distress related to a visible difference, but more research is needed that includes comparisons of YPF to other health- and societal resources and long-term follow-ups. Our study also constitutes an addition to research as, compared to interventions for somatic diseases, there is a lack of studies exploring the cost-effectiveness of psychological interventions.