Thesis advisor: Lillie R. Albert / In mathematics education, there is an imperative for more just and equitable experiences in mathematics spaces, as well as ongoing efforts to move classroom instruction toward mathematical inquiry. While Mathematics Teacher Educators (MTEs) are expected to support multiple initiatives in mathematics education, they are particularly responsible for the professional learning of teachers and teacher candidates. MTEs must therefore prepare and support the professional learning of teachers to achieve twin goals. This study was designed to understand how MTEs envision their roles in supporting development of teachers across MTEs’ many professional functions in their work toward the twin goals of equity and inquiry. The findings suggest that identifying the forms mathematical knowledge takes is important for mathematical inquiry and that interrogating these forms can be used to counter pervasive social myths about who can do mathematics. Further, MTEs articulated three interrelated values for application of mathematics inquiry teaching for justice and equity: creating space, supporting sense-making, and naming how power and privilege have operated and continue to operate in mathematics spaces. Finally, MTEs described how mathematics inquiry practices are a mode for understanding the world and can be used to promote equity by uncovering biases and assumptions. These findings suggest a promising avenue for leveraging mathematical inquiry to increase equitable outcomes in mathematics spaces. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.