Sydney has been described as a ‘City of Suburbs’. Indeed, the process of suburbanisation is arguably one of the most important developments in Australia’s post-invasion history. Kilometre after kilometre of suburb has for decades dominated Sydney and other Australian capital cities cultural landscapes while suburbia has been the heartland of bourgeois ideology that has been dominant for more than two generations. Metropolitan Sydney’s phenomenal suburban expansion during much of the twentieth century has been explored by a small number of urban historians. But the impact and importance of suburbanisation in and around Sydney – by far the largest annual metropolitan investment item – has still to attract the attention it deserves. This article looks at the physical evolution of suburban Sydney and its ideological underpinnings.