Action research is a powerful tool for educators seeking to address instructional challenges in linguistically diverse classrooms. This session introduces the fundamentals of action research, specifically designed for K–12 educators who may be new to research practices but are eager to enhance their instruction through data-informed decision-making. A central focus of the session is how this action research process empowers content teachers to support multilingual students by identifying language-related challenges, testing targeted strategies, and making data-informed instructional adjustments. Building on this foundation, the session also emphasizes the importance of planning lessons with both language and content objectives (Wright, 2019). This includes aligning instruction with English language proficiency standards, identifying the language demands of various content areas, crafting appropriate language objectives, differentiating instruction based on English proficiency levels, strategically incorporating home languages, and developing formative assessments that measure both language growth and content understanding. Action research offers a structured approach to implementing, assessing, and refining these practices over time. Participants will leave with: A simple action research planning template based on Effron and David’s model Practical strategies for collecting and using data in multilingual classrooms Ideas for collaborating and sharing findings with colleagues References Effron, J. M., & David, S. A. (2019). Action research for improving practice: A practical guide (2nd ed.). Corwin. Wright, W. E. (2019). Foundations for teaching English language learners: Research, theory, policy, and practice (3rd ed.). Caslon Publishing.