Aim <p>Public health campaigns, including Australian cancer screening programs, are increasingly promoted online through government websites. The accessibility of these initiatives for people with intellectual disability is unknown. However, a lack of accessible information about available services is an important barrier to cancer screening for this group. This study aimed to investigate the accessibility of online information for cancer screening programs.</p> Subject and methods <p>Australian government health websites promoting the national breast, bowel, and cervical screening programs were identified and web pages were evaluated for their compliance with Web Content Accessibility Guidelines 2.0, cognitive accessibility guidelines, readability recommendations, and where relevant, compliance with Easy Read guidelines.</p> Results <p>The most common accessibility errors included low-contrast colors, missing alternative text, broken links, and excessive content. Readability was a consistent issue, with most materials written at levels considered too high for both people with intellectual disability and the general population. The limited number of documents that were readily available in Easy Read did not follow guidelines.</p> Conclusion <p>These findings demonstrate that government public health initiatives currently fail to meet the communication and information needs of people with intellectual disability. This places the population at risk of continued under-screening and fails to uphold their right to information about their healthcare. The creation and dissemination of accessible materials should be a priority for governments and health services.</p>