Background: The association between spirituality and emotional health has been well documented in healthy individuals. A small literature has shown that spirituality plays a role in well‐being for some breast cancer (BC) survivors; however, this link is virtually unexplored in partners/spouses of survivors. The current study aimed to assess the relationship between spirituality, emotional distress, and post‐traumatic growth for BC survivors and their partners using a dyadic analyses approach. Methods: A total of 498 couples who were 3–8 years post‐BC diagnosis were recruited from the Eastern Oncology Group database. Results: For BC survivors and their partners, greater levels of spirituality were associated with increases in their own post‐traumatic growth. There was no relation between BC and partner spirituality and their own emotional distress, but partner's spirituality was associated with reduced occurrence of intrusive thoughts in the BC survivor. In contrast, BC survivors' spirituality was found to be wholly unrelated to partner's mental health and adjustment. Conclusions: Following diagnosis and treatment, spirituality appears to associate with positive growth in BC survivors and their partners. However, BC survivor and partner spirituality seem to be ineffective at impacting the other's post‐traumatic growth or emotional distress, with the exception of intrusive thoughts. Dyadic analysis takes into account the reciprocal influence of close relationships on health and is an important and under‐utilized methodology in behavioral oncology research and clinical practice. Copyright © 2016 John Wiley & Sons, Ltd.