Background The ease of access to pornography has made its use common among adolescents. Although sexual and gender minority (SGM) (eg, gay, transgender) adolescents may be more prone to use pornography owing to sexual orientation–related information seeking and/or scarcity of potential romantic or sexual partners, relatively little attention has been paid to their pornography use and to the quantitative examination of the similarities and differences between heterosexual, cisgender (HC) and SGM adolescents’ pornography use characteristics. Aim The aim of the present study was to compare SGM and HC adolescents’ pornography use considering potential sex differences. Methods We used a sample of 2,846 adolescents (52.5% girls; Mage = 14.5 years, SD = 0.6), which was collected as part of an ongoing longitudinal study on adolescents’ sexual health. Data were analyzed with 5 groups: HC boys; HC girls; SGM boys; SGM girls; and SGM non-binary individuals. Outcomes Adolescents completed a self-report questionnaire about sexual and gender minority status and pornography use (ie, lifetime use, age at first exposure, and frequency of use in the past 3 months.) Results Results indicated significant differences between all groups: 88.2% of HC boys, 78.2% of SGM boys, 54.2% of SGM girls, 39.4% of HC girls, and 29.4% of SGM non-binary individuals reported having ever viewed pornography by the age of 14 years. SGM girls indicated a significantly younger age at first pornography use than HC girls, but this difference was not significant among boys. SGM boys reported the highest (median: many times per week), whereas HC girls reported the lowest (median: less than once a month) frequency of pornography use. Clinical Translation Results suggest that SGM and HC boys' pornography use characteristics are rather similar, whereas SGM and HC girls’ pornography use patterns may be considered different presumably because of the varying underlying motivations (eg, using pornography to confirm sexual orientation). Strengths & Limitations Self-report measures and cross-sectional designs have potential biases that should be considered. However, the present study involved a large sample of adolescents including SGM adolescents, a population group that is understudied. Conclusion Approximately two-thirds of teenagers had gained their first experience with pornography in the present sample, and 52.2% reported using it once a week or more often in the past 3 months, indicating that pornography use may play an important role in both HC and SGM adolescents’ sexual development. Gender-based differences concerning pornography use seem to be robust regardless of SGM status.