Thesis (PhD)--University of South Australia, 2010. Children are widely regarded as society's future, although the 'here and now' of their childhood receives dismissive treatment in policy development, especially in the realm of urban policy and planning. This results from a complex interplay between social constructions of childhood; notions of citizenship and approaches to public policy-making, and it is particularly evident in urban planning policy because of the particular significance urban environments hold for children. The thesis addresses three research questions. What are the unifying themes across social constructions of childhood, children's citizenship status and the treatment of children in public policy in modern democratic societies? Does urban planning policy recognise children as consumers of the physical environment and local resources, recipients of services, and as participants in shaping the life of the community? Could the public policy interests of children as citizens of the urban environment be advanced through expanding existing conceptualisations of citizenship and adopting more socially inclusive approaches to public policy-making? These questions are addressed through examining discourses of childhood, citizenship theory and policy-making, via document analysis and case studies of local area planning. Four case studies in the cities of Brisbane and Canberra, Australia, examine the place occupied by the rights, needs and interests of children across social and physical domains, and the opportunities for children to participate in shaping their urban environment. Examination of aspects of urban planning from selected international locations draws attention to the potential impact of socio-political acceptance of the concept of the child citizen, and explores support for children's exercise of social agency. A paradigm where children are viewed as in a 'process of becoming', embedded in constructions of childhood, eclipses an appreciation of the social efficacy of children in the 'here and now'. This subjugated status of children is reinforced by, and supports, constructions of citizenship which are generally silent about the social position of children, and approaches to public policy-making which do not reflect a just relationship between the state and children. The findings from study of local area planning illustrate a lack of prominence to the space, service and land use needs of children, and exclusion of children from opportunities and processes which contribute to policy-making. The strongest evidence of attention to children is found where issues of social order may arise or where there are concerns for safety and health. Policy filtering, competition between groups and the dominance of sectional interests are powerful influences in public policy-making. Children are treated as secondary beneficiaries, by association of their needs and interests with more influential forces. Policy recognition of children as participants in shaping the life of the community is patchy and disjointed. In sum, the study findings suggest that sustained recognition of children in public policy-making requires sufficient conditions, created by acknowledgement of children's independent social agency; a reinvigorated conception of citizenship as a journey which is inclusive of children; recognition of children's rights, in particular participation rights; and the adoption of socially inclusive approaches to policy-making. Accordingly, I point to the need for sufficiently integrated and multi-layered change across conceptions of citizenship, constructions of childhood and approaches to policy-making to sustain an enduring shift in the treatment of children in public policy.