Objective Few descriptions of physical disability in childhood-onset SLE (cSLE) exist. We sought to describe disability in a large North American cohort of patients with cSLE and identify predictors of disability. Methods Sociodemographic and clinical data were obtained from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry for patients with cSLE enrolled between May 2010 and October 2014. The Childhood Health Assessment Questionnaire (CHAQ) was used to assess disability and physical functioning. Chi-square tests were used for univariate analyses, and multivariate logistic regression was used to assess predictors of disability. Results We analyzed data for 939 patients with cSLE. The median and mean CHAQ scores were 0 and 0.25, respectively, and 41% of the cohort had at least mild disability. Arthritis and higher pain scores were significantly associated with disability as compared to those without disability ( p < 0.001). In multivariate logistic regression analysis, low annual income, arthritis, and higher pain scores were associated with disability at baseline. Conclusions Disability as measured by baseline CHAQ was fairly common in cSLE patients in the CARRA Legacy Registry, and was associated with low household income, arthritis, and higher pain scores. In addition to optimal disease control, ensuring psychosocial supports and addressing pain may reduce disability in cSLE. Further study is needed of disability in cSLE.