Background: There is paucity of research from Australia about comorbidity in older people with intellectual disability (PwID). This paper examines the burden of chronic diseases and associated sociodemographic correlates in a cohort of PwID aged 60+. Methods: A cross-sectional survey was used with community-dwelling older PwID in urban/rural regions of two Australian states. Recruitment was undertaken via a multi-prong approach and each subject (N = 391; 236 urban/155 rural) personally interviewed. Results: Findings show older PwID experience considerable multimorbidity (X = 3.8; 53.5% had 2-6 conditions). Conditions included arthritis (40%), diabetes (26%), cardiovascular diseases (23.6%), asthma (16.1%), carcinomas (10.0%) and mental health disorders (34.5%). Conclusions: There was significant multimorbidity in older PwID, with evolution of life trajectories of select conditions associated with socioeconomic disadvantage and heath facility access barriers. Greater scrutiny of progressive health debilitation leading into older age and increased engagement by healthcare systems is required earlier in the lives of PwID.