<p>Beliefs in the future, encompassing hope and optimism, are vital for adolescents’ development and well-being. This study investigates how significant others—including parents, teachers, and peers—influence the future beliefs of left-behind children in underdeveloped rural areas of China. A sample of 525 left-behind children, ranging from grades 7 to 9, completed measures of interpersonal relationships, psychological resilience, and future beliefs. Structural equation modeling was employed to examine both direct and indirect effects. The results indicated that supportive relationships are positively associated with future beliefs, though the effects vary across relationship types. Parent-child relationships exerted both direct and indirect effects on children’s future beliefs through resilience, whereas peer and teacher relationships influenced future beliefs solely through resilience. Furthermore, resilience had a strong direct effect on future beliefs. These findings highlight the importance of enhancing supportive social environments to foster positive future orientations among left-behind children.</p>