The female-headed household is a new vulnerable group associated with health inequality. The purpose of this study was to analyze psychological well-being and related factors among Korean female-headed households based on age stratification. This was a secondary analysis of data extracted from the fifth Korean Working Conditions Survey (2017), which included a total of 9084 female-headed households. Their psychological well-being was measured by the WHO-5 well-being index. A total of 39.8% of female-headed household workers were psychologically unhealthy. Among them, 2.2% of those aged 15–30 years old, 8.1% aged 30–50 years old, and 29.5% over aged 50 years old were unhealthy. In the age group of 15–30 years old, depression/anxiety was negatively associated with psychological well-being. In the age group of 30–50 years old, living alone, musculoskeletal pain, fatigue, and depression/anxiety were negatively associated with psychological well-being. In the age group over 50 years old, low education level, living alone, low income, musculoskeletal pain, fatigue, and depression/anxiety were negatively associated with psychological well-being. The psychological well-being perceived by female households is complex and goes beyond economic poverty and dependent burdens. Therefore, a multidimensional support strategy should be included in the concept of social deprivation, and a preventive approach is needed to establish a support system.