The purpose of this study was to conduct formative research to inform the development of an app, that would simultaneously engage youth and adults, to prevent dating and sexual violence (DSV) and alcohol use (AU). Participants (N = 56) were high school students, parents/guardians, and professionals (e.g., school personnel) from across the United States who participated in online focus groups. Overall, participants had positive perceptions of the utility, helpfulness, and effectiveness of an app to prevent DSV and AU among high school students. Participants provided in depth information about both the content (e.g., local rates of DSV and AU) and features (e.g., skills‐based, inclusion of incentives, help button) that the app should include. These preliminary data suggest that future research to develop and pilot an app for both youth and adults to prevent DSV and AU among high school students is warranted.