This systematic review synthesizes quantitative evidence on school factors associated with physical activity (PA) participation in children and adolescents with disabilities (CAD). A comprehensive search was conducted in four databases, and studies were included if they quantitatively measured PA levels and examined school factors associated with PA participation among CAD. Methodological quality was assessed, and a semiquantitative synthesis was performed. Twenty-four studies with good to excellent methodological quality were included. Five primary and 21 secondary school factors linked to PA engagement in CAD were identified: school time structure, school PA characteristics, school physical environment, school social environment, and school organizational factors. Among these, four factors of the school time structure (i.e., physical education time, recess time, lunch time, and before- and/or after-school time) showed the most consistent positive associations with PA. This review highlights the critical role of structured school time for school-based PA promotion in CAD.