This study analyzes the effect of self-efficacy on depression among older adults with disabilities and verifies the moderating effect of social support on it. This study selected 140 people with disabilities aged 65 years and older based on the data from a survey by the Gyeonggi-do Association of Persons with Physical Disabilities in 2021. A hierarchical multiple regression model was used to analyze the paths between major variables and verify their moderating effect. The results show the following. First, self-efficacy among older adults with disabilities had a positive effect on their depression―a lower level of self-efficacy resulted in a higher level of depression. Second, social support had a negative association on depression― a higher level of social support led to a lower level of depression. Third, social support moderated the effect of self-efficacy on depression. This study suggests that it is necessary to provide a practical intervention that considers psychological factors such as self-efficacy and the socioenvironmental resource of social support in developing programs and policies intended to prevent depression among older adults with disabilities.