Purpose: This descriptive research study aimed to identify the factors that influence depression according to household type (older adults who live with a spouse, adult children, or alone).Methods: A total of 9,790 older adults were selected and analyzed using the 2020 National Older Koreans data. A Rao-Scott x2 test was conducted to evaluate the differences in the individual, health-behavior, and mental-health factors according to family structure. A complex samples logistic regression was used to analyze the factors that influence depression according to family structure.Results: Depression according to family structure was in the order of older adults who live alone, with adult children, or a spouse (p<.001). Total income, number of chronic diseases, hospitalization, exercise, and suicide ideation were identified as depressive factors for older adults who live with adult children. Employment, subjective health status, number of chronic diseases, hospital visitation, hospitalization, drinking, suicide ideation, economic status satisfaction, and cultural life satisfaction were depressive factors for older adults who live with a spouse. Employment, subjective health status, hospitalization, drinking, suicide ideation, and cultural life satisfaction were depressive factors (p<.05) for older adults who live alone.Conclusion: It is necessary to detect depression early and operate a mental health program considering the family structure of older adults.