Background and objectives: One-person households are the fastest growing family type in Korea. They bring social concerns such as weakened social integration, increasing poverty and social isolation. They are not homogeneous but heterogeneous groups depending on their socio-demographic characteristics including generation. This study compared the life satisfaction level as well as factors affecting it among the three one-person household generations Methods: The 13th wave of the Korea Welfare Panel dataset with 1,187 respondents was utilized. For data analysis Chi-square test, analysis of variance and hierarchical regression analysis were employed. Generations are divided into three, namely young adult (20-39), the middle-aged (40-64) and the elderly (65 and over). Result: The life satisfaction level was highest among the young adult one-person household generation, followed by the middle-aged and the elderly generation. The common factors affecting life satisfaction of the three generations were physical as well as mental health, including self-esteem and depression. However, there were more factors different from generation to generation. As for the young adult, age, religion, and smoking were significant. As for the middle aged and the elderly, gender (male) and income were significant. Additionally, age, home-ownership and drinking were significant to the elderly generation. Conclusions: As there are differences as well as similarities among the three generations, policies for one-person households need to be devised considering these findings. For all generations, both physical and mental health policies are needed. For young adult strengthening social relations, providing decent jobs, and promoting anti-smoking policy are major agenda, and for the middle-aged and the elderly, assisting in social capital accumulation (for male), providing stable jobs and diverse leisure activities, and securing income. Additionally, for the elderly, expanding the social security system and housing support are needed.