This interpretive multiple case study examined how K-16 world language teachers (N = 12) incorporated social justice issues into their curriculum and instruction and the factors that supported and constrained this work. The findings revealed that the participants experienced supports and impediments that shaped their agency to enact social justice education. These factors included the professional community of the school or institution, the students' perspectives and contributions, and existing curriculum and curricular resources. The discussion advances an ecology of teacher agency in which teachers take up a stance toward social justice and navigate structures to creatively reconstruct their teaching and the world language curriculum. Implications are discussed for teacher education, in-service professional development, and educational research.