Adolescent female victims of sexual assault must often disclose their victimization to trusted adults to seek positive physical and mental health outcomes; however, adolescent girls face unique barriers to disclosure, and they are less likely to disclose compared to adult women. Media interventions could be useful in motivating adolescent girls to feel more efficacious about disclosing sexual assaults. Self-efficacious messages in media that model disclosure behavior could motivate adolescent girls to feel more confident disclosing information about an assault and seeking positive health outcomes. This study used quasi-experimental methods to test the effect of a YouTube vlog containing a self-efficacy message about sexual assault disclosure. Results indicate that exposure to the self-efficacious message leads to higher sexual assault disclosure efficacy among adolescent girls who identify with self-efficacious media characters (B = −.0867, SE = .059, 95% CI [−.2318, −.0033]), albeit indirectly through perceived discrimination of sexual assault victims and approach coping behaviors. Appropriate interventions targeting disclosure of sexual assault by adolescent girls could include a more holistic view of disclosure and use new mediums like YouTube vlogs to deliver self-efficacious messages.