Higher intakes of individual antioxidants such as vitamins A, C, and E have been linked to mortality in the general population, but the association of overall antioxidant intake with mortality especially in depressed adults remains unclear. We aimed to investigate whether the dietary overall antioxidant intake is associated with all-cause and cause-specific mortality among depressed adults. This study included 3051 US adults with depression, who participated in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Patient Health Questionnaire-9 (PHQ-9) was used to define depression and evaluate depression severity. The dietary antioxidant quality score (DAQS) and dietary antioxidant index (DAI) were calculated based on the intakes of vitamins A, C, and E, zinc, selenium, and magnesium. A higher DAQS and DAI were significantly associated with lower depression scores (PHQ-9) (all P-trend < 0.05). For individual antioxidants, significant negative associations of vitamins A and E with all-cause mortality were observed. For overall antioxidant intake, the DAQS and DAI were inversely associated with all-cause and cancer mortality. Compared with participants in the lowest categories of DAQS and DAI, the corresponding HRs (95% CIs) in the highest categories were 0.63 (0.42–0.93) and 0.70 (0.49–0.98) for all-cause mortality and 0.39 (0.17–0.87) and 0.43 (0.21–0.88) for cancer mortality, respectively. The overall dietary antioxidant intake was beneficially associated with all-cause and cancer mortality in depressed adults. These findings suggest that comprehensive dietary antioxidant intake may improve depressive symptoms and lower mortality risk among adults with depression.