In this essay, the author describes principles for equitable mathematics teaching practices for English Language Learners (ELLs) and outlines guidelines for materials to support such practices. Although research cannot provide a recipe for equitable teaching practices for ELLs, teachers, educators, and administrators can use this set of research-based principles and guidelines to design equitable mathematics instruction, developing their own approaches to supporting equitable practices in mathematics classrooms. The recommendations presented use a complex view of mathematical language as not only specialized vocabulary but also as extended discourse that includes syntax, organization, the mathematics register, and discourse practices. The principles and guidelines stress the importance of creating learning environments that support all students (but specifically those learning English) in engaging in rich mathematical activity and discussions.