Previous research has established a link between social media and risky drinking behavior, indicating that social networking sites provide exposure to drinking norms that predict attitudes and willingness towards alcohol use. However, despite the growing usage of social media, there is little research on the effects of social networks (other than Facebook) on risky sexual behaviors. Risky sexual behaviors have been previously defined as behaviors that increase the risk of negative outcomes associated with sexual contact such as unwanted pregnancies or sexually transmitted infections. The purpose of the current study is to describe the relationship between having an account with various social networking platforms and risky sexual behavior among young adults. For the present study, risky sexual behavior was defined as having sex with casual partners, having multiple sexual partners, and the lack of condom usage. We hypothesize that being a member of currently popular social media platforms will be positively associated with the aforementioned risky behaviors, while this relationship will be mediated by positive attitudes held towards risky sex. To test our hypotheses, a national sample of 1002 young adults aged 18-20 (53.6% female) were asked to complete a one-time online survey on social media use, health behaviors and risk behaviors, including sexual behavior. Participants reported which social media platforms (Facebook, Twitter, Instagram, or Snapchat) they have accounts with and their attitudes regarding casual sexual behavior, multiple sexual partners, and condom use. Additionally, participants reported on their sexual behaviors within the past 3 months, including: number of casual sexual partners, number of total sexual partners, and the frequency of condom use during sexual encounters. Results of this study may provide a better understanding of the nature and dangers of social media usage, and can help shape protective actions or interventions for reducing sexual behavioral risk.