Purpose: We aimed to identify the effects of hearing-related characteristics, physical activity, and depression on health-related quality of life in middle-aged adults with hearing loss using a secondary analysis of large-scale domestic survey data. Methods: This secondary data analysis study, targeted middle-aged adults between the ages of 40 and 64 from the 8th data of the Korea National Health and Nutrition Examination Survey (2020). Data were extracted from general characteristics (gender, age, education level, marital status, economic activity status, income level), health-related characteristics (recent drinking, current smoking, body mass index, subjective health, perceived stress, presence of comorbidities, activity restriction), hearing-related characteristics (degree of hearing loss, subjective hearing status, tinnitus persistence, subjective tinnitus level, eardrum abnormality), levels of depression, and health-related of quality of life. Data analysis was performed using SPSS 28.0. Results: Health-related quality of life was significantly lower in patients subjectively uncomfortable with hearing (t=2.70, p=.008). Subjective hearing status (r=-.18, p=.004) and depression (r=-.29, p=.026) were significantly negatively correlated with health-related quality of life. Subjective hearing status (t=-3.78, p<.001), physical activity level (t=2.20, p=.030), and depression (t=-3.27, p=.001) were identified as significant influencing factors of healthrelated quality of life. Conclusion: Health in middle-ages determines health conditions in old age. Thus, it is necessary to develop and apply hearing loss management programs to prevent deterioration in physical activity and depression and to improve the quality of life of middle-aged adults.