As only half of adolescents in the United States receive school-based sex education that meets the minimum standard articulated in national goals (Lindberg and Kantor LM, Adolesc Health 70:290–297, 2022), young people often turn to other sources of sexual health information, including online sources. Although adolescents view teachers, parents, friends, and medical professionals as more trusted sources of sexual health information (Jones and Biddlecom, J Health Commun 16:112–123, 2011), they also seek out online sexual health information (OSHI) specifically for more sensitive, potentially embarrassing, or stigmatizing topics. With a rise in the prevalence of Internet use and advances in innovative, accessible digital technologies, especially over the last decade, adolescents have greater access to OSHI at their fingertips than ever before. This chapter describes the tools (i.e., Internet use and device usage/ownership) adolescents use for OSHI, the latest trends related to OSHI-seeking, including data on sources of such information (e.g., websites, apps, social media) and topics sought, as well as benefits and risks of OSHI, such as exposure to misinformation, bias, and inaccuracies. We end by describing directions for future OSHI research and offering recommendations for clinicians/providers, educators, and policy makers.