This study aimed to examine attitude toward aging as a potential mediator of the relationship between personality factors and mental health in terms of depression and life satisfaction among older adults. A cross-sectional study was conducted with 438 Ethiopian elderly individuals aged 60 to 69. The results of the regression-based path analysis showed that after adjusting for demographic data, the relationship between agreeableness and depression in older adults was partially mediated by attitude toward aging. Likewise, attitude toward physical change due to aging and psychological growth subscales jointly mediated the correlation between neuroticism and depression. However, a significant direct path between neuroticism and depression persisted. On the contrary, openness had no significant direct association with depression apart from an indirect through psychosocial loss. The link between life satisfaction and agreeableness as well as openness to experience were partially mediated by psychosocial loss. Therefore, a person’s attitude toward aging and personality characteristics should be taken into consideration while designing interventions for managing mental health issues among older adults.