This study examined the mediating roles of academic motivation and resilience in the relationships between psychological well-being, perceived academic support, and academic achievement among first-year students at Injibara University. A correlational design was employed to address these objectives. Instruments included adapted versions of Ryff’s Psychological Well-Being Scale, Gutiérrez et al.’s Perceived Academic Support Scale, Vallerand et al.’s Academic Motivation Scale, and Cassidy’s Academic Resilience Scale. Participants comprised 503 students (403 males, 100 females), selected via multi-stage stratified random sampling. Instrument validation involved translation and transcultural adaptation to ensure cultural relevance, followed by a pilot study with 200 students. Confirmatory factor analysis (CFA) assessed model fit using indices such as the Comparative Fit Index (CFI > 0.90), Root Mean Square Error of Approximation (RMSEA < 0.08), and chi-square/degrees of freedom ratio (< 3), confirming structural validity. Internal consistency was established with Cronbach’s alpha (> 0.70) and composite reliability (> 0.70), while convergent and discriminant validity were supported through average variance extracted (AVE > 0.50) and inter-construct correlations. Structural equation modeling (SEM) results demonstrated that psychological well-being exerted both direct and indirect effects on academic achievement, with academic motivation and resilience partially mediating this relationship, while perceived academic support showed solely an indirect effect, fully mediated by academic motivation and resilience. These findings highlight the importance of fostering psychological well-being and targeted support to enhance motivation and resilience, improving academic outcomes. The study offers recommendations for educational interventions, acknowledges limitations, and proposes future research directions.