Background Formative experiences in adolescence lay the foundation for healthy and pleasurable romantic and sexual relationships. Exposure to pornography may affect these experiences. Objective We aimed to synthesize evidence published in the past decade on the relationship between exposure to pornography and sexual behavior (earlier age of first sex [<16 years], condomless sex, past-year multiple partners [>1], lifetime multiple partners [>1], group sex, sexual aggression including forced sex, paid sex, teenage pregnancy, and history of sexually transmitted infection) in adolescents aged between 10 and 19 years. Methods We identified 19 eligible studies by searching MEDLINE, PsycINFO, Cochrane, CINAHL, Embase, and Web of Science databases from January 2010 to November 2022. Results Out of 8 studies that assessed earlier age of first sex, 5 studies, including 1 longitudinal study, found a statistically significant association with exposure to pornography. Given that most studies were cross-sectional or had substantial limitations, causal inference could not be made. Also, exposure to pornography was not measured consistently. The evidence was conflicting or insufficient to draw any conclusions regarding other outcomes. Conclusions More quantitative research is needed to elucidate the association between pornography exposure and sexual behavior, and sex education should adopt evidence-based approaches to minimize the potential harms from pornography. Trial Registration PROSPERO International Prospective Register of Systematic Reviews CRD42021227390; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227390