BACKGROUND: Married or long-term partnered patients with chronic diseases generally have better outcomes than unmarried patients, likely due to the potential for multifaceted support. However, the impact of marital status on multiple sclerosis (MS) radiographic disease burden is currently unknown. OBJECTIVE: To compare total white matter hyperintensity lesion volumes, periventricular lesion volumes, and whole brain and grey matter volumes in married and unmarried people with MS (PwMS). METHODS: We utilized multivariable linear regression to assess for differences in brain atrophy and lesion volumes between these two groups controlling for sex, MS disease duration in years, hypertension, history of smoking, alcohol consumption, history of depression and/or anxiety, and medication possession ratio (MPR). RESULTS: Married PwMS had significantly lower total lesion volumes (β = - 6.3, 95% CI - 12.1 to - 0.5, p = 0.033), lower PV lesion volumes (β = - 6.1, 95% CI - 11.7 to - 0.6, p = 0.030), higher normalized whole brain volumes (β = 38.3, 95% CI 6.0 to 70.7, p = 0.021), and higher normalized grey matter volumes (β = 20.9, 95% CI - 0.7 to 42.6, p = 0.058) than unmarried PwMS. CONCLUSION: Being married may be associated with improved MS outcomes as evidenced by decreased radiographic MS disease burden.