Citizenship of children implies that they can assume political co-responsibility in society on an ongoing basis, as well as influence societal processes and political decisions, not only in the future, but in the present. To understand children as citizens means that they can do so in a particular, but equal and equivalent way as adults. This must be accompanied by the development of a culture of children's rights in society that takes children seriously as legal subjects and grants them, in particular, participation rights, which enable them to make their own decisions in all areas of life and in society including questions, which touch the interests of adults. This requires not only the recognition of the children's competencies, but also the creation of conditions, which enable children to develop their agency competencies and use them practically. First, this chapter outlines what can be understood by citizenship in general and what problems are associated with the term. Then it discusses concepts of citizenship that relate directly to children and their relatively impotent social status. Finally, with regard to children, it explains what the term citizenship from below means, and how this can emerge from social movements of children, principally those from the Global South.