BackgroundWhile dispositional optimism is a critical psychological resource for university students navigating academic and developmental transitions, its social correlates particularly the specific dimensions of friendship quality in non-Western contexts remain underexplored.ObjectiveThis study investigated the predictive power of distinct friendship quality dimensions on optimism among undergraduate students in a Middle Eastern context, controlling for demographic variables.MethodsA quantitative cross-sectional design was employed with a sample of 450 undergraduate students (63.3% female) from Jadara University, Jordan. Participants completed validated Arabic versions of the McGill Friendship Questionnaire–Friend's Functions (MFQ-FF) and the Life Orientation Test–Revised (LOT-R). Data were analyzed using two-way ANOVA and hierarchical multiple regression.ResultsInitial analyses revealed that female and second-year students reported significantly higher levels of both friendship quality and optimism. However, hierarchical regression demonstrated that after controlling gender and academic year, friendship quality explained a substantial additional 28.6% of the variance in optimism. Notably, reliable alliance, a dimension characterized by trust, dependability, and mutual commitment emerged as the sole significant independent predictor of optimism (β = 0.730, p < .001). Furthermore, the predictive effects of demographic variables were fully subsumed upon the inclusion of reliable alliance in the final model.ConclusionThe findings highlight the important association between trustworthy peer relationships and optimism among emerging adults in collectivist cultures. Demographic disparities in student optimism appear to be largely driven by variations in reliable alliances, suggesting that university counseling and peer-support interventions should prioritize targeted trust-building initiatives to enhance psychological well-being.