This study examines the relationships between the Big Five personality traits, self-presentation strategies on social media, social comparison orientation, and life satisfaction. Grounded in personality theory and social comparison theory, the research proposes an integrative model explaining how stable dispositional traits shape identity regulation behaviors and psychological outcomes within digitally mediated environments. A quantitative cross-sectional survey design was employed, and data were collected from a sample of 400 undergraduate students from universities in Egypt and Saudi Arabia. The study utilized established measurement scales, including the Big Five Inventory (BFI), the Social Comparison Orientation scale, the Satisfaction with Life Scale (SWLS), and validated measures of self-presentation strategies on social media. Data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results reveal that Big Five personality traits significantly predict self-presentation strategies and social comparison orientation on social media platforms. Additionally, self-presentation strategies positively influence social comparison orientation. The findings also indicate that social comparison orientation has a significant negative effect on life satisfaction, suggesting that increased comparison tendencies within social media environments may reduce individuals’ overall well-being. However, the mediating role of social comparison orientation between personality traits and life satisfaction was not statistically supported. Overall, the results highlight the central role of personality structures in shaping online identity regulation behaviors and emphasize the psychological implications of social comparison processes within social media contexts.