Background Physical activity (PA) is beneficial for all people, yet people affected by multiple sclerosis (MS) find regular PA challenging. These people may include individuals with the disease who have moderate‐to‐severe disability and their family caregivers. For researchers and clinicians to effectively promote PA among caregiver/care‐recipient dyads with moderate‐to‐severe MS, a comprehensive understanding of the shared PA experiences of these dyads would be beneficial. Objective We explored shared experiences of caregiver/care‐recipient dyads affected by moderate‐to‐severe MS about PA and directions for intervention. Methods Six focus groups with 23 people with moderate‐to‐severe MS and 12 family caregivers were conducted. Data were analysed using a constant comparative approach. Results Three major themes emerged as follows: (i) PA is a continuum, (ii) cycle of disengagement and (iii) cycle of adjustment. The first theme captured the dyads understanding that PA falls along a continuum ranging from highly structured to unstructured activities. Cycle of disengagement captured the experiences of dyads engaging in little or no PA. These dyads perceived internal and external issues as drivers of the cycle of disengagement, while availability of supportive programmes and services or people helped the dyads to break out of the cycle. When the cycle of disengagement was broken, the dyads described moving towards the cycle of adjustment, where they were able to learn skills and take action to incorporate PA into daily routines. Conclusion This research highlights the need to adopt an integrative approach that acknowledges the caregiver/care‐recipient dyad with moderate‐to‐severe MS as a focus for PA intervention.