This study investigated the relationship between night work, supervisor support, and depressive symptoms among full-time wage workers, with a focus on gender differences. A nationwide sample of 22,422 full-time wage workers from the Sixth Korean Working Conditions Survey (2020-2021) was analyzed. Experiences of night work were categorized into 5 groups based on the number of night work days per month: 0, 1-5, 6-10, 11-15, and 16-31. Depressive symptoms were evaluated using the 5-item World Health Organization Well-Being Index. Supervisor support was assessed with 5 items. Workers who engaged in 1-5 days (prevalence ratio [PR], 1.23; 95% CI, 1.12-1.36) and 6-10 days (PR, 1.17; 95% CI, 1.06-1.30) of night work per month exhibited a higher prevalence of depressive symptoms than those without night work. After stratifying by supervisor support levels, workers with 1-5, 6-10 and 11-15 days of night work per month were more likely to experience depressive symptoms compared to those without night work in the low supervisor support group. In contrast, no association was found between night work (≥ 6 days) and depressive symptoms in the high supervisor support group. Furthermore, gender differences were notable: female workers with 6-10 days (PR, 1.45; 95% CI, 1.23-1.70), and 11-15 days (PR, 1.43; 95% CI, 1.08-1.90) of night work per month exhibited a higher prevalence of depressive symptoms, whereas their male counterparts did not. This pattern of gender difference was also found among those with low supervisor support. Supervisor support may mitigate the adverse effects of night work on depressive symptoms among full-time wage workers, with differences manifested across genders.