Purpose: This study aimed to identify the impact of health literacy on adherence of medication among older adults living alone and to determine the mediating effect of e-health literacy in the relationship between the two variables. Method: A total of 91 older people living alone who visited a general hospital and welfare center participated, and data collection was conducted from July 20, 2023 to August 30, 2023. Descriptive statistics, t-test, ANOVA, Pearson’s correlations, Model 4 of PROCESS macro were used for data analysis. Results: Health literacy of older adults living alone was found to have a significant effect on adherence of medication (β=.33, p<.001) and e-health literacy (β=.34, p<.001). E-health literacy was found not to mediate the relationship between health literacy and adherence of medication (Indirect effect: β=-.02, 95% confidence interval [-.08~.02]). Health literacy was significantly different depending on age (F=6.87, p=.002), education background (F=10.36, p<.001), and monthly income (F=7.98, p<.001). There was a significant difference in adherence of medication based on age (F=4.38, p=.015). Also, e-health literacy had significant differences in age (F=10.05, p<.001), education background (F=7.91, p<.001), and monthly income (F=7.38, p<.001). Conclusion: When providing education to older adults living alone to improve adherence of medication, medical staff and nurses should identify health literacy, provide repetitive medication education tailored to the level of health literacy of each elderly living alone, and critically receive indiscriminate health information from the Internet.