Purpose: Implementation of screening program may lead to increased health disparity within the population if participation differs by socioeconomic status. In Korea, colorectal cancer screening is provided at no or minimal cost to all people over 50 by National Cancer Screening Program. We investigated colorectal cancer screening participation rate and its trend over the last 10 years in relation to disabilities. Materials and Methods: We linked national disability registration data with National Cancer Screening Program data. Age, sex-standardized participation rates were analyzed by type and severity of disability for each year, and factors associated with colorectal cancer screening participation were examined by multivariate logistic regression. Results: Age, sex-standardized participation rate in people without disability increased from 16.2 to 33.9% (change, +17.7), but it increased from 12.7% to 27.2% (change, +14.5) among people with severe disability. People with severe disabilities showed a markedly lower colorectal cancer screening participation rate than people without disability (adjusted odds ratio [aOR], 0.714; 95% confidence interval, 0.713 to 0.720). People with autism (aOR, 0.468), renal failure (aOR, 0.498), brain injury (aOR, 0.581), ostomy (aOR, 0.602), and intellectual disability (aOR, 0.610) showed the lowest participation rates. Conclusion Despite the availability of a National Cancer Screening Program and overall increase of its usage in the Korean population, a significant disparity was found in colorectal cancer screening participation, especially in people with severe disabilities and or several specific types of disabilities. Greater effort is needed to identify the barriers faced by these particularly vulnerable groups and develop targeted interventions to reduce inequality.