Two preregistered experiments with 2,733 U.S. high school students (age range = 13–19 years) compared the impact of different messages on adolescents’ motivation to control social media use (SMU). A traditional message emphasized the benefits of avoiding SMU, whereas a values‐alignment message framed controlling SMU as being consistent with autonomy and social justice. Compared to no message or a traditional message, in both studies, a values‐alignment message led to greater motivation to control SMU immediately afterward, and in Study 2, awareness of “addictive” social media designs 3 months later. As hypothesized, values‐alignment messaging was more motivating for girls than boys. Results offer preliminary support for leveraging adolescents’ drives for autonomy and social justice to motivate self‐regulation of SMU.