A type 2 diabetes (T2DM) diagnosis has been referred to as a “wake-up call” but subsequent behavioural change may be influenced by place of residence. Random effects within-between regressions were applied to 130,926 participants in the 45 and Up Study. T2DM diagnoses effected change in the odds of short sleeps and meeting vegetable and alcohol consumption guidelines, but not changes in physical activity. Each of these behaviours varied geographically and were patterned by area disadvantage and geographic remoteness. Impacts of T2DM diagnosis on behavioural change were not found to be geographically contingent, though analysis of specific environmental attributes is warranted.