Background: Relationship education (RE), often employed for adults, has become increasingly available for teenagers. However, non-romantic relationships are rarely assessed as a potential outcome domain influenced by RE. Objective: Informed by life course theory and the ecological systems perspective, this study examines the influence of RE on both dating and parent-adolescent relationships, and the associations between such changes. Methods: Using a one-sample, non-controlled design, we conducted repeated measures analysis of covariance, and hierarchical linear regression analyses to examine the influence of RE participation on 3658 ethnically diverse adolescents' knowledge and use of healthy skills in their parent-adolescent and dating relationships and whether these changes are linked. Results: Results indicate significant and positive influences on participants' knowledge and use of healthy relationship skills in their parent--adolescent and dating relationships. Further, results indicate that change in the current dating relationship is associated with concurrent change in the parent-adolescent relationship. Conclusion: The results of this study provide preliminary evidence for a spillover effect of relationship education efforts, which are traditionally focused on the youth dating relationships, to parent-adolescent relationship dynamics. Future research considering multiple domains of RE outcomes for youth is warranted and future RE development and implementation may consider integrating parents to maximize program outcomes.