Objective: The present study aimed to clarify the circumstances under which activity restriction (AR) is associated with depressive symptoms among patients with osteoarthritis (OA) and their spouses. Method: A total of 220 older adults with OA and their caregiving spouses participated in the study. The actor–partner interdependence model (APIM) was used to examine the associations between AR stemming from patients’ OA and the depressive symptoms of patients and spouses. The potential moderating role of marital satisfaction also was examined. Results: After accounting for pain severity, health, and life stress of both patients with OA and spouses, higher AR was associated with more depressive symptoms for both patients and spouses. In regard to partner effects, patients whose spouse had higher AR reported more depressive symptoms. In addition, the association of spouses’ and patients’ AR and their own depressive symptoms was moderated by their marital satisfaction. For both patients and spouses, the associations between their own AR and depressive symptoms were weaker for those with higher levels of marital satisfaction compared with those with lower levels of marital satisfaction. Discussion: This pattern of findings highlights the dyadic implications of AR and the vital role of marital satisfaction in the context of chronic illness.