As the number of pupils who are multilingual and multicultural continues to increase in the United States, finding ways to best support these learners’ writing has become a priority. This project explores the creation and use of third spaces that support writing in three diverse urban classroom contexts. Ethnographic case studies reveal the ways in which teachers created third spaces for multicultural and multilingual students’ voices to be heard (Bakhtin, 1986; Dyson, 2003). Findings suggest that co-constructing third spaces can contribute to a writing pedagogy that includes multilingual and multicultural student discourse(s) while expanding the social and practical purposes for writing. These findings have implications for teacher educators, researchers, and classroom teachers with regard to the power of co-constructed spaces where students’ lives and languages are used as the foundation for merging school and local networks.