The study aims to analyze the mediating role of job satisfaction in the relationship between personality traits and employees’ organizational commitment in the public sector in Hanoi city. From the data provided by 337 employees working in the public sector, the structural equation model (SEM) was applied to evaluate the impact of personality traits on job satisfaction, organizational commitment, and the relationship between job satisfaction and organizational commitment. The result shows that a positive relationship between personality traits, job satisfaction, and organizational commitment. The study suggests some significant policy implications for organizations in the public sector to increase job satisfaction and organizational commitment.