Introduction <p>Cancer is a condition that poses a threat to public health and adversely affects all aspects of patients’ quality of life. One strategy to mitigate the negative effects of the disease is social support. This study was conducted to determine the relationship between social support and resilience with quality of life in patients with breast cancer.</p> Methods <p>This analytical cross-sectional study was carried out in the province of Gilan (northern Iran) from September 2021 to February 2022. Data were collected from breast cancer patients referred to the Hematology and Radiotherapy Department of Razi Hospital in Rasht, affiliated with the Guilan University of Medical Sciences, using four questionnaires: a demographic form, the Cancer and Davidson Resilience Questionnaire (CD-RIS), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Quality of Life Questionnaire (C30-QLQ). Participants were selected through consecutive sampling. Data were analyzed using SPSS version 22, with normality assessed using the Kolmogorov-Smirnov and Shapiro-Wilk tests, and relationships among variables were examined using the Spearman nonparametric test. A significance level of <i>p</i> &lt; 0.05 was considered for all statistical analyses.</p> Results <p>A total of 89 women with breast cancer participated in the study, with a mean age of 44.15 ± 17.9 years, and more than half held a diploma or associate degree. Most patients were in stage 2 of cancer (43.8%), and chemotherapy was the most common treatment intervention (67.4%). The findings indicated that there was no significant relationship between quality of life and demographic characteristics such as age, education level, occupation, cancer stage, and type of treatment. Furthermore, Spearman’s correlation analysis revealed that the functioning score—a component of quality of life—was significantly inversely related to the total scores of social support and resilience (<i>p</i> = 0.041 and <i>p</i> = 0.028, respectively), whereas the overall quality of life score exhibited a significant positive correlation with the acceptance subscale of resilience (<i>p</i> = 0.007). Logistic regression analysis also indicated that family support (a subscale of social support) and personal competence (a subscale of resilience) were significant predictors of patients’ functioning and symptomatology (<i>p</i> = 0.05 and <i>p</i> = 0.019, respectively).</p> Conclusion <p>The results of this study indicate that breast cancer patients require assistance in adapting to their condition. Receiving and strengthening social support from family and friends plays a crucial role in helping patients cope with and combat the disease. Enhancing perceived social support and quality of life in these patients should be given serious consideration to prevent social, psychological, and physical complications and to improve overall functioning.</p>