Background and objectives: The relationship between pain and psychiatric conditions in children and adolescents has been understudied. This study aimed to investigate the influence of gender on the association between pain and psychiatric diagnoses, as well as the specific relationship between pain and attention deficit/hyperactivity disorder (ADHD), in a sample of adolescents from the general population. Additionally, the study explored whether pain frequency or intensity in individuals with ADHD was influenced by coexisting psychiatric disorders and ADHD medications. Methods: This cross-sectional study included 1608 conveniently sampled Swedish upper secondary school students aged 15–19 years. Data were collected at the end of 2020 using the electronic "Mental and Somatic Health without borders" survey. Results: A significant positive association (p < 0.001) was observed between pain frequency, intensity, and the presence of any psychiatric diagnosis. Female adolescents reported more frequent and intensive pain in the groups with or without any psychiatric diagnosis and in those with ADHD, however the presence of a psychiatric diagnosis had a comparatively lesser impact on pain frequency in females when compared to males. In adolescents with ADHD, pain frequency, but not intensity, showed a significant further increase. Moreover, the presence of coexisting depression and/or anxiety further heightened the association between pain frequency and ADHD. Notably, common ADHD medications did not have a significant impact on pain experiences. Headache emerged as the most prevalent type of pain across all groups of adolescents. Back pain specifically appeared as the next most common type of pain among adolescents with ADHD. Conclusion: The findings suggest a positive association between pain and the presence of psychiatric diagnoses, including ADHD, in adolescents. Gender modified this association. Back pain arised specifically coupled to ADHD. Common ADHD medications did not show a significant impact on pain experiences in this study. These results highlight the importance of a holistic approach to child and adolescent care. © 2023 The Author(s)