Purpose: The incidence of breast cancer in premenopausal women in South Korea is higher compared to the West. This study aimed to identify factors associated with the health-related quality of life (HRQoL) among survivors with premenopausal young breast cancer undergoing endocrine therapy by examining the effects of menopausal symptoms, social support, and resilience on HRQoL. Methods: Cross-sectional study was used to select survivors with breast cancer undergoing endocrine therapy. The study instruments used included a basic information questionnaire, Menopause Rating Scale, Multidimensional Scale of Perceived Social Support, Connor-Davidson Resilience Scale, and Health-Related Quality of Life Instrument with 8 items. Researchers utilized independent t -tests, one-way analysis of variance, Pearson's correlation coefficients, and multiple linear regression to analyze the data. The data were collected from August to September 2021, and the questionnaire was administered via a link posted on a bulletin board of an online breast cancer survivors community. Finally, 133 questionnaires were included in the final analysis. Results: Among 150 participants, 133 completed the questionnaires. HRQoL was higher in the groups with a monthly income of >= 5 million KRW (beta = 0.231, p = .011), fewer menopausal symptoms (beta = -0.399, p < .001), and higher social support (beta = 0.170, p = .038), and lower in the group receiving endocrine therapy and OFS (beta = -0.192, p = .010). The explanatory power for HRQoL of premenopausal young breast cancer survivors undergoing endocrine therapy was 38.3% (F = 10.634, p < .001). Conclusion: Breast cancer survivors should be supported to participate in economic activity, utilize rehabilitation and intervention programs to alleviate menopausal symptoms, and benefit from a social support network formed by the hospital, community, and government.