Background/Objectives: Digital technologies have transformed how young adults in romantic relationships communicate, develop intimacy, and manage control. Although these technologies facilitate connection, they may enable surveillance, control, and aggression. This study examined associations of psychological distress and romantic love myths with digital dating violence while controlling for problematic social media use. Methods: This observational, cross-sectional study included 336 university students aged 18–25 years. Participants completed the Cyber-Violence in Adolescent Couples Scale, adapted for young adults (Cib-VPA), the Depression Anxiety Stress Scales-21 (DASS-21), the Scale of Myths of Romantic Love (SMRL), and the Bergen Social Media Addiction Scale (BSMAS). Differences between men and women, partial correlations, pooled regression models testing the Sex × DASS-21 × SMRL interaction, and sex-stratified regression models were examined. Results: Women reported higher levels of anxiety, depression, stress, psychological distress, cybercontrol victimization, cyberaggression victimization, cybercontrol perpetration, and total victimization. Men showed stronger endorsement of romantic love myths. Formal pooled comparisons indicated that the DASS-21 × SMRL interaction differed by sex for victimization–cyberaggression, perpetration–cybercontrol, and total victimization. Sex-stratified models showed significant interactions for several dimensions of digital dating violence. Simple slopes showed that psychological distress was positively associated with total perpetration among men and women and with total victimization among women when romantic love myth endorsement was high. Conclusions: Psychological distress and romantic love myths appear to be associated with digital dating violence. Prevention programs should support psychological well-being, challenge romantic love myths, and improve recognition of cybercontrol as a form of intimate partner violence.