Objective: The aim of this study is to examine the prevalence of coronary heart disease (CHD)–related disability (hereafter also “disability”) and the impact of CHD risk factors on disability in older adults in the Republic of Ireland (ROI) and Northern Ireland (NI). Method: Population attributable fractions were calculated using risk factor relative risks and disability prevalence derived from The Irish Longitudinal Study on Ageing and the Northern Ireland Health Survey. Results: Disability was significantly lower in ROI (4.1% vs. 8.8%). Smoking and diabetes prevalence rates, and the fraction of disability that could be attributed to smoking (ROI: 6.6%; NI: 6.1%), obesity (ROI: 13.8%; NI: 11.3%), and diabetes (ROI: 6.2%; NI: 7.2%), were comparable in both countries. Physical inactivity (31.3% vs. 54.8%) and depression (10.2% vs. 17.6%) were lower in ROI. Disability attributable to depression (ROI: 16.3%; NI: 25.2%) and physical inactivity (ROI: 27.5%; NI: 39.9%) was lower in ROI. Discussion: Country-specific similarities and differences in the prevalence of disability and associated risk factors will inform public health and social care policy in both countries.