Purposes: This study aims to identify the characteristics of the study subjects by age, including non-elderly people aged 19 to 65, pre-elderly people aged 65 to 75, and elderly people aged 75 and over, and to identify factors affecting health literacy based on an investigation of the health literacy level of each study group. This study would like to find out the differences in health literacy factors by age group. Methodology: The HLS-EU-Q16, developed by the World Health Organization Regional Office for Europe for the Health literacy Survey of Europeans, will be applied in this study. Findings: We found that scores decreased in order of nonelderly, pre-elderly, and late-elderly in health care, disease prevention, and health promotion. In addition, health literacy was lower in the older age group, and higher health literacy was associated with being unmarried, higher education, and higher income. In terms of influencing factors, marital status was significantly different in the non-elderly group, and higher education level was associated with higher health literacy. Practical Implications: The results of this study show that health literacy levels are low in all age groups, and efforts to improve health literacy in younger, older, and non-elderly groups are needed. It is expected that age-specific health literacy strategies can help improve the level of understanding and utilization of health information, improve health, and lead a healthy life.