The aim of this study was to assess the physical activity (PA) patterns of youth with intellectual disabilities (ID). PA was monitored for 7 days in 70 participants, 5–15 years old, using accelerometers. There were 32 participants included in the final analysis. Habitual PA and the number of continuous bouts accrued for a range of bout lengths (5–600 s) for light (LPA), moderate (MPA), and vigorous (VPA) PA were calculated. Multivariate analysis of covariance was used to assess differences in the number of continuous bouts by sex, age, and ID group and between week and weekend days. Participants exhibited short sporadic bursts of activity. The number of continuous bouts decreased as the intensity and duration increased. Few differences in PA patterns were reported by sex, ID group, and age group and between week and weekend days, possibly due to the generally low PA levels in this population.