The number of English Language Learners in the United States continues to increase, yet the number of teachers trained to support ELLs does not. The lack of expertise in this area could have a negative impact on academic achievement. Teachers across the nation, including those at Driscoll Middle, a mid-size suburban middle school in the Southeastern United States, could benefit from training focused on strategies to support this learning group. Research indicates that effective professional learning holds the potential to positively impact on teacher efficacy. Teacher efficacy is directly related to teacher performance and student achievement. This qualitative study examined educators' perceptions of the possible impact of professional learning on the efficacy of teachers of English Language Learners (ELLs). Participants in this study included teachers, school leaders, and district instructional coaches. Three specific questions guided this research: 1) How do teachers perceive their preparedness to deliver effective instruction to English Language Learners? 2) What specific professional learning will teachers require to be equipped? 3) What does an AR team learn as members collaborate to equip teachers with literacy and language-focused professional learning? In order to examine the research questions, an AR team worked through the steps of planning, action, observation, and reflection of the implementation of a professional learning program. Data was collected through stakeholder interviews, surveys, assessments, and observations (professional learning communities, classroom instructions, etc.). Previous literature suggested that as the English Language Learner population increases nationwide, public school systems must effectively develop their teachers to deliver instruction that meets the needs of all learners. Conclusions about this action research demonstrated that implementation of specific, targeted professional learning can positively impact teacher efficacy. This work contributes to research surrounding teacher effectiveness in working with diverse populations and offers recommendations for delivering an effective professional learning plan to build capacity. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]