["Journal of Intellectual Disability Research, Volume 70, Issue 6, Page 588-598, June 2026. ", "\nABSTRACT\n\nBackground\nAdults with intellectual disabilities (IDs), particularly those who reside in community living arrangements (CLAs), are at high risk for these chronic diseases. Sedentary behaviour (SB) is an emergent, independent risk factor for several chronic diseases including cardiovascular and metabolic conditions. SB may represent a potent behavioural target to mitigate chronic disease risk in adults with ID who live in CLAs. Limiting the development of interventions to address SB is a lack of understanding of device‐estimated SB patterns. Also not clear are the individual‐level determinants of SB in this high‐risk group of CLA residents with ID. The current study sought to address these knowledge gaps.\n\n\nMethods\nA cross‐sectional observational study design was used to characterize SB patterns and individual‐level determinants of SB in adults with ID living in CLAs. Thirty‐eight adults from 24 different CLAs wore activPAL devices for 1 week to enable device estimates of SB. activPAL data were processed, and the study outcomes of daily time spent in SB, SB bout lengths, sedentary breaks and prolonged SB were generated. Participants also completed an online survey to assess individual factors, which included demographics, independence, programming and health status. Univariate statistics were used to describe SB patterns and logistic regression models were used to ascertain the association between individual factors and SB variables.\n\n\nResults\nOn average, the sample were aged 44.79 years (SD = 14.9), and 60.53% were male. The sample were highly sedentary: 47.37% engaged in prolonged SB, the daily average time in SB was 7.46 h (SD = 2.18), and an average of 32.4 daily SB bouts (95% CI = 28.9, 35.9) lasted 17.7 min (95% CI = 13.8, 21.7). Participants requiring more assistance with ADLs were more likely to have longer uninterrupted sedentary bouts (95% CI = 0.169, 1.721; β = 0.945; p = 0.018) and total daily duration of SB (95% CI = 4.58, 20.21; β = 12.394; p = 0.003). Those with less than a high school education had sedentary bouts that were ~15 min longer (95% CI = 3.21, 25.69; p = 0.013).\n\n\nConclusions\nAdults with ID living in CLAs spent almost 8 h of their waking day in SB. Those with lower levels of independence and education were more likely to have higher levels of SB. CLAs may represent a critical opportunity for targeted, place‐based interventions to reduce time spent in SB.\n\n"]