Purpose : Mental well-being is a critical component of occupational health, particularly for skilled workers in agriculture, forestry, and fisheries who face unique physical and environmental stressors. This study aimed to identify key determinants of mental well-being for this workforce in South Korea. Methods : Using the data from the 7th Korean Working Conditions Survey, this study analyzed a nationally representative sample of skilled agricultural, forestry, and fishery workers. Multiple linear regression analyses were performed to examine associations among mental well-being and a range of demographic, occupational, and health-related variables. Results : Mental well-being was significantly positively associated with being female, higher monthly income, better subjective health, greater satisfaction with the work environment, higher exposure to physical demands at work, and increased job enthusiasm. Conversely, working on Sundays and experiencing sleep disturbances were negatively associated with mental well-being. Among all variables, job enthusiasm showed the strongest positive association. The regression model accounted for a statistically significant proportion of the variance in mental well-being. Conclusions : Mental well-being among skilled workers in agriculture, forestry, and fisheries is shaped by a complex interplay of personal, occupational, and health-related factors. Targeted interventions that enhance the work environment, support health management, and foster job engagement are essential to promote mental well-being of this population. These findings provide actionable insights for developing tailored occupational health policies and workforce training programs.