Little is known about physical activity (PA) participation in people with advanced multiple sclerosis (MS). The purpose of this study was to (a) characterize self-reported PA levels and (b) explore how PA levels might differ based on sociodemographic (e.g., gender) and clinical (e.g., MS clinical course) characteristics in people with advanced MS. We used a cross-sectional online survey design with 101 participants. PA was measured using the Physical Activity Scale for Individuals With Physical Disabilities. The mean score on the scale was 4.5 (SD = 5.9) metabolic equivalent hours per day. There was a significant difference in scores based on employment, population density, living situation, disability, and assistive-device type (all p <
.05). PA levels were higher in those who were employed, lived alone, required bilateral support for mobility, and were manual wheelchair users (all p <
.05). This study highlights low PA levels in people with advanced MS and potential variables that might impact PA in this MS subgroup.