Early prevention strategies are needed to mitigate the high risk of cardiovascular disease in adolescents with type 1 diabetes (T1D). Residential neighbourhood features can promote healthy lifestyle behaviours and reduce cardiovascular risk, but less is known about their role in lifestyle behaviours in adolescents with T1D, and no studies use comparisons to healthy controls. We examined associations between residential neighbourhood features and lifestyle behaviours in adolescents with T1D and healthy controls. Data from CARDEA, a cross-sectional study of 100 adolescents with T1D (14-18 years) from a paediatric diabetes clinic in Montreal, Canada, and 97 healthy controls, were analysed. Outcomes included physical activity and sedentary behaviour (accelerometry), screen time and sleep duration (questionnaires), and dietary habits (24h recalls). Cluster analysis of selected neighbourhood indicators computed for participants’ postal codes resulted in two neighbourhood types: central urban and peri-urban. Central urban neighbourhoods were characterised by very high population density, high active living index, numerous points of interest, higher social deprivation, higher residential mobility, and lower median household income compared to peri-urban neighbourhoods. Associations of neighbourhood type with lifestyle behaviours were estimated with multiple linear regressions and interactions by T1D status were tested. Living in central urban neighbourhoods was associated with greater daily minutes of moderate-to-vigorous physical activity (B = 8.61, 95% CI [1.79, 15.44]) compared to living in peri-urban neighbourhoods. No associations were observed for other lifestyle behaviours, and no statistically significant interactions were found between neighbourhood type and T1D status. Features that characterize central urban built environments appear to promote physical activity in adolescents, regardless of T1D status.