Background Patients diagnosed with breast cancer were reported to have high levels of psychosocial distress and poor quality of life (QOL). Mindfulness is believed to improve QOL and reduce psychological distress in various populations, but its unique association with QOL and psychological distress in women with breast cancer has yet to be established. Objectives This study was conducted to examine the relationship of mindfulness with depression, anxiety and QOL of women diagnosed with breast cancer. Methods A descriptive, correlation design was used. Results A sample of 234 Jordanian women completed the study. 24% of the participants scored above the cut‐off for clinical depression, 36.3% scored above the cut‐off for clinical anxiety, and 35.5% scored above the cut‐off for poor QOL. Mindfulness accounted for significant unique variance in depression, anxiety and QOL above and beyond the variance accounted for by the demographic variables, clinical variables and social support. Conclusion The current study provided preliminary evidence for the relationship of social support and mindfulness with the psychological well‐being and QOL among Jordanian women with breast cancer. Future research may want to tailor an intervention that combines social support and mindfulness‐based interventions and identify their benefits to support Jordanian women with breast cancer.