The field-based mentoring of student teachers is often an idiosyncratic and nuanced practice in which mentors' conceptualizations of their interactions with student teachers are generated through personal experiences with teacher education. If teacher educators and programs are to strengthen the tie between campus and field-based teacher education, in effect bridging the perceived disconnect of campus-based learning and the "realities" of the classroom, acknowledging these divergent perspectives is a first step in providing transformative learning experiences for student teachers. To that end, in this article the authors use recent empirical research into the school-based mentoring of student teachers to describe three conceptions of mentor teacher roles and responsibilities. Centered in the notion that mentoring is often a socially constructed practice, these roles include a consideration of the mentor teacher as (1) instructional coach, (2) emotional support system, and (3) socializing agent. Through a discussion of these conceptions, the hope is to further the conversation about ways to provide a common language between university and field-based teacher educators.