BackgroundSo far, studies on workplace mental health have only focused on work-related environmental risk factors, disregarding both protective and individual factors of employees. Therefore, we aimed to identify character strengths that act as protective factors against depressive moods and suicidality in Korean employees.MethodsIn total, 84 male and 151 female employees (aged 19–50 years) reported their sociodemographic characteristics; depressive symptoms, as measured by the Beck Depression Inventory-II; suicidality, as measured by the Korean version of the MINI International Neuropsychiatric Interview suicidality module; and character strengths, as measured by the 24 Character Strength Alphas on the Values in Action Survey-72. We conducted a hierarchical logistic regression, in which depressive mood and suicidality served as the categorical outcome variables.ResultsIn females, scores on the “curiosity” (B = 1.107, Wald = 10.207, odds ratio = 3.026, p = .001) and “love” (B = .862, Wald = 5.767, odds ratio = 2.367, p = .016) sub scales of the 24 Character Strength Alphas on the Values in Action Survey-72 were statistically significant predictors of having depressive mood. Additionally, females’ scores on “judgment” (B = − 1.405, Wald = 5.663, odds ratio = .245, p = .017) and “kindness” (B = − 1.456, Wald = 6.486, odds ratio = .233, p = .011) were protective factors against suicidality. In males, the “love” (B = 1.746, Wald = 4.279, odds ratio = 5.729, p = .039) score was a predictor of having depressive mood, while “teamwork” (B = − 2.204, Wald = 4.666, odds ratio = .110, p = .031) and “creativity” (B = − 1.384, Wald = 4.202, odds ratio = .251, p = .040) scores were protective factors against having depressive mood and suicidality, respectively.ConclusionsWe suggest that focusing on “judgement” and “kindness” in female employees, and “teamwork” and “creativity” in male employees, and engaging in activities that use these strengths at the workplace can be protective factors against depression and suicidality. Future research should focus on developing interventions to promote these character strengths among employees at the workplace.