*English Learners in secondary school settings often face discrepancies in opportunities and outcomes. Methods to address these discrepancies are grounded in an instrumental approach to instruction, wherein educational practitioners are understood to require methodological intervention in the form of professional development by a more experienced expert. However, repositioning practitioners as knowledge generators who understand their contexts as potential sites of inquiry is seen as a more humanizing and democratic approach to professional learning. This qualitative Practitioner Inquiry study explored the language ideologies articulated and embodied within the context of a Practitioner Inquiry Community by practitioners supporting *English Learners at a Northern California high school. It also sought to understand how participation in a Practitioner Inquiry Community mediates language ideologies. This study utilized Cultural-historical activity theory, critical post-structural sociolinguistics, ideology-in-pieces, and "inquiry as stance" as frameworks for analyzing data. Findings demonstrated that practitioners draw on language ideologies across a continuum ranging from more hegemonic to more counterhegemonic throughout their participation in an inquiry community. This study concludes that participation in a practitioner inquiry can mediate language ideologies and conceptualizations of support for *English Learners. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]