Multiple sclerosis (MS) has a major impact on the relationship of couples living with the illness. Although some positives of dealing with MS as a couple have been identified, MS has been associated with higher rates of relationship breakdown and worse Quality of Life (QOL) for both people in the relationship, especially if the person with MS experiences a decline in mental or physical health or develops disability. Modification of lifestyle-related risk factors has been associated with improved outcomes for people with MS, including physical and mental health-related QOL, and these improved outcomes may lead to improved experiences for their partners. We aimed to explore the perspectives and experiences of the partners of people with MS, when the people with MS had undertaken an intensive residential workshop regarding healthy lifestyle, to understand the impact of MS and lifestyle modification on these partners' experiences of their relationship. Within the framework of Heidegger's interpretive phenomenology, semi-structured interviews were thematically analysed. Participants were in a spousal relationship with people with MS who had attended an intensive residential workshop regarding modification of lifestyle-related risk factors between 2002 and 2016. Participants lived in Australia, New Zealand, the United Kingdom and Europe. Three major themes were identified relating to the couple's relationships: providing support, remaining connected and togetherness. Aspects of these themes, not commonly previously reported, included the personal and relationship benefits experienced from providing support with lifestyle modification, improved communication, and the resultant greater sense of closeness. These experiences of partners of people with MS improve our understanding of both the complexities of living with MS and adopting lifestyle modification, and suggest some potential benefits to relationships.