The study aimed to explore the relationship between religiosity, psychological distress, and quality of life (QOL) in Saudi breast cancer patients. Utilizing a multi-center cross-sectional design, 277 patients were recruited. Patients completed questionnaires assessing religiosity, depression, anxiety, suicidality, and QOL. Results revealed a high prevalence of depression (35.7%) and anxiety (18.1%), with no significant variations in internal religiosity across different health stages, despite high levels of perceived social support. Suicidal ideation was reported by a small proportion of patients (2.5%). Multivariate analysis identified anxiety, therapy side effects, and breast symptoms as significant predictors of depression, while depression and previous psychiatric treatment predicted anxiety levels. QOL assessments indicated that body image received the highest satisfaction ratings, while sexual function received the lowest. These findings highlight the critical need for integrated mental health support in the treatment regimen of breast cancer patients.