The red-bellied black snake is native to the east coast of Australia, where it is one of the most commonly encountered snakes. It can be found in the urban forest, woodland, plains, and bushland areas of the Blue Mountains, Canberra, Sydney, Brisbane, Melbourne, Cairns, and Adelaide. The Macquarie Marshes mark a western border to its distribution in New South Wales, and Gladstone in central Queensland marks the northern limit to the main population. To the south, it occurs across eastern and central Victoria, and extends along the Murray River into South Australia. Disjunct populations occur in the southern Mount Lofty Ranges in South Australia and in North Queensland.