The Asia Pacific Journal of Social and Behavioral Sciences, Volume 23, features a Special Issue that foregrounds teacher competence and professional learning as central concerns in contemporary education. Bringing together empirically grounded and practice-oriented studies, the issue examines how professional development initiatives influence teachers’ knowledge, behaviors, and instructional practices across diverse educational contexts. Anchored in socio-behavioral perspectives, the contributions frame professional learning as a dynamic and transformative process rather than a one-off training activity. The articles explore varied settings, including out-of-field teaching, child development programs, multigrade classrooms, and public-school environments, highlighting how educators experience, negotiate, and sustain professional growth. Key themes across the issue include the integration of ICT in teaching, the use of action research as a vehicle for reflective practice, and the development of pedagogical content knowledge in science, mathematics, and English education. Several studies also investigate changes in teacher research engagement, documenting behavioral shifts in attitudes, capability, and productivity following targeted professional development. Innovative instructional approaches, such as the use of comics as a socio-behavioral tool for economic literacy, further demonstrate how professional learning can translate into effective and context-sensitive classroom practice. Overall, this Special Issue advances a cohesive body of evidence in ongoing discussions on teacher development, offering insights for educators, school leaders, and policymakers seeking to strengthen teaching quality through sustained and context-responsive professional learning.