This study examines children’s position in urban design through public space, the right to the city, spatial justice, and child participation. Modern urbanization and adult-centred planning position children not as active subjects of urban space, but as passive users needing protection and direction. This limits children’s relationship with streets, neighbourhoods, and public open spaces, weakening their participation, mobility, and visibility in urban life. The study theoretically analyses the child-city relationship. It is grounded in Habermas’s approach to public space, Lefebvre’s and Harvey’s discussions on the right to the city, Jacobs’s perspective on street life and public safety, and Hart’s Ladder of Participation. Children’s role in producing urban space is discussed through the child-friendly city approach, built environment education, and everyday spatial practices. The study emphasizes that a child-friendly city cannot be limited to playgrounds or safe facilities. Children’s right to the city concerns not only access to safe spaces, but also visibility in streets, neighbourhoods, public open spaces, and decision-making processes. Safety is evaluated not through controlled spaces separating children from the city, but through lively street life, natural surveillance, and everyday encounters. The study argues that children should be recognized as active subjects who experience and transform the city and whose views should inform design decisions. Child-friendly urban design should include physical interventions, participation mechanisms, everyday mobility, and built environment awareness. The study highlights the need for an inclusive urban design approach that strengthens children’s visibility and participation in public space while addressing spatial, administrative, and pedagogical dimensions together.