In the context of increasing realizations of the fragility of democracy, the possibilities and accomplishments of youth activist projects across material and virtual spaces and sites continue to flourish. Research on this work is situated in the rich scholarly traditions of critical youth studies and critical youth literacies as well as in theories of civic engagement, public pedagogy, participatory politics, cosmopolitanism, and relational mobilities. Many youth projects draw on the resources of arts, digital media, and critical multiliteracies to participate, in material ways, in public and political life. Taking up issues such as citizenship for immigrant youth, homelessness, and poverty, young people powerfully create critical, social, and political narratives that resonate within and beyond their own communities. Theorizing this work in relation to public engagement, spatiality, and mobilities deepens our understanding of those moments when youth in community and educational sites create powerful transmediated counter-narratives about their lives and worlds—the ways they incorporate both local and global understandings to create these new forms of political participation. And the work itself underscores the need for more equitable access to various multimodal and digital resources and the importance of youth access to public and mediated spaces. Schools and educators are called to create pedagogical spaces that invite students’ subjectivities, locations, and creative uses of material resources to engage in local and larger public dialogues, counter dominant cultural ideologies, address multiple publics, and create new forms of political participation.