This quantitative study explored teacher perceptions of professional learning community dimensions, teacher self-efficacy, and collective efficacy. Professional learning communities (PLCs) have been shown to positively impact teacher self-efficacy and collective efficacy, all supporting student achievement. The overarching question guiding this study was, "What relationships exist among professional learning community dimensions, teacher self-efficacy, and collective efficacy and what differences exist in teacher perceptions in elementary, middle, and high schools; TAP and Non-TAP schools; and high poverty and low poverty schools?" The study sample included 57 schools within one large metropolitan southern school district. Three data collection measures were utilized to assess teacher perceptions including the Professional Learning Community Assessment-Revised, the Teachers' Sense of Efficacy Scale, and the Teacher Efficacy Beliefs Scale-Collective Form. Data analyses included descriptive and inferential statistics and resulted in eight major findings with finding Implications related to conceptual/theoretical frameworks, leadership and practice, and future research. These findings support professional learning communities as positively influencing teacher self-efficacy and collective efficacy; PLCs as contributing to school improvement; and school variables, such as poverty level, PLC implementation, and school level indeed influence efficacy. Additionally, study findings inform district leaders, school leaders, and teachers regarding implementation of PLC practices in enhancing teacher self-efficacy and collective efficacy and supporting school improvement.