This study examined the relationship between daily time spent using social media and substance use in a national sample of 563 emerging adults from the United States (18- to 22-year-olds, 50% female, 63% non-Hispanic White). Results revealed that males reported more social media use and more substance use in comparison to females. In addition, greater daily social media use was related to more alcohol consumption, more problematic alcohol use, and more frequent drug use. A significant gender × social media use interaction was also observed for drug use, revealing that greater daily social media use was significantly related to more frequent drug use for females but not for males. Results from this study emphasize the importance of considering different types of social media in relation to substance use and abuse during emerging adulthood and the need to examine these relations by gender.