Abstract: Teacher professional development (PD) is the continuous process of improving teachers’ skills, knowledge, and practices throughout their careers. This holistic approach aims to enhance teaching effectiveness and positively impact student learning. The purpose of the research was to examine the Influence of Teachers’ Professional Development on the Implementation of Competency Based Curriculum (CBC) in Homa Bay Town Sub County, Homa Bay County, Kenya. The study was grounded on Gross Theory of Curriculum Implementation (Nawaz & Abar, 2021). The study used a mixed-method approach with a convergent parallel design. The target population included 71 public primary schools, 71 head teachers, 639 teachers, and one sub-county director. Sampling techniques included simple random sampling for schools, stratified random sampling for teachers, and purposive sampling for head teachers and the sub-county director. Data collection involved questionnaires, interview guides, and Observation checklists. Reliability was confirmed through the test-retest method and internal consistency, while validity was ensured through pilot testing and triangulation. The Cronbach alpha coefficient was 0.713, indicating reliability. Qualitative data were analyzed thematically, and quantitative data were analyzed using descriptive statistics with the help of SPSS version 23. Findings revealed that teachers had received CBC training, but its short duration raised concerns about effectiveness. Teachers generally had a positive attitude towards CBC, appreciating its focus on practical skills and talent discovery. However, challenges such as insufficient instructional materials, large class sizes, and inadequate training were significant obstacles. The study highlighted the need for continuous professional development, sufficient resources, and improved training programs for successful CBC implementation. Future research should examine the long-term impact of professional development on teachers' effectiveness and the role of community and parental involvement in supporting CBC adoption and overcoming resource and preparedness challenges in Homa-Bay County. 

Keywords: professional development, Public primary schools, Competency-based curriculum, Implementation