Technology-facilitated sexual violence (TFSV) is a ubiquitous societal problem with negative health consequences. Child and Adolescent Psychiatric (CAP) patients are burdened with more violence exposure than other groups, but more work is needed to chart their exposure to TFSV specifically and to understand how it relates to their mental health. In this study, we aimed to investigate the occurrence of unwanted online sexual solicitation (UOSS) in a young Swedish psychiatric sample. We also aimed to measure the associations between psychiatric symptoms and exposure to UOSS, offline sexual harassment, cyberbullying, and offline bullying. We also aimed to analyze possible differences between boys and girls. Our results show a high occurrence of UOSS (48.61%), which is higher than in the general population. UOSS was significantly higher among girls (57.31%) than boys (20.59%), but boys in the CAP group were burdened with more UOSS victimization than boys in general. Co-occurrence of UOSS with other types of offline and online harassment was substantial. UOSS, together with age and offline sexual harassment, predicted anxiety and depressive symptoms among both girls and boys. UOSS also showed a significant interaction effect with gender, suggesting that boys exposed to UOSS suffer higher levels of anxiety and depressive symptoms than girls exposed to UOSS. Preventing and treating mental health difficulties needs to consider contextual circumstances such as exposure to sexual violence online.