Children and adolescents with disabilities are at a high risk of experiencing symptoms of mental illness, specifically anxiety, secondary to their primary diagnoses. Among children and adolescents without disabilities, physical activity (PA) is associated with lower odds of experiencing symptoms of anxiety and can positively impact symptoms of anxiety through reducing stress, improving memory, sleep, and overall mood. The evidence base examining the relationship between PA and anxiety in children and adolescents with disabilities is limited. Thus, the aim of this systematic review was to summarize and describe literature assessing the relationship between physical activity and anxiety in children and adolescents with disabilities. Of the initial 15,670 identified articles, five met the inclusion criteria to be included in the data extraction. The included studies ranged in design, including longitudinal (n=2), cross-sectional (n=3), and retrospective (n=1), with one longitudinal study also including a cross-sectional component. All five studies used varying self-report measures of PA and anxiety. A total of 712 children and adolescents with disabilities were included across the five studies (age range 6 to 20; 57.5% boys; >80% physical disabilities). A small inverse relationship was reported across all five included studies, indicating higher PA levels to be associated with lower levels of anxiety, however, two were not significant. Future research should focus on the use of validated self-report measures of PA and anxiety, device-based measures of PA, prospective studies, and examining the PA-anxiety relationship in populations of children and adolescents with disabilities beyond physical disabilities.