This research investigated the influence of the Competency Based Curriculum on attainment of 21st century competencies among learners in Kisumu West Sub-County. The research problem was based on a growing concern among researchers and educators that the learner centred curriculum had initially been largely flawed, hurried and lacking proper strategies as well as wide consultation. Major education stakeholders such as parents also received the Competency Based Curriculum with a lot of negativity and resistance claiming that the system is financially oppressive and burdensome. Learners too were caught in between and almost lost confidence in the curriculum due to the cynical talks about it from their parents, social media and the general public. The study therefore strived to identify the degree to which the competency-based curriculum has improved learners’ creative thinking. The study was guided by the constructivist theories. Mixed research methodology was adopted. A descriptive survey design was used. Purposive sampling was used to identify 32 schools out of 105 primary schools. A total of 133 respondents were involved in various segments of data collection tools; focus group discussion schedules, questionnaires, observation schedules and document analysis schedules, mainly to elicit information from school principals, teachers and parents within public, private, special and integrated schools. The study instruments were found to be reliable with a Cronbach’s Alpha 1.0. Collected data was analysed using both descriptive and inferential statistics. The data was presented in tables and figures. The coefficients the independent variable was positive and statistically significant. The study found creative thinking the most significant variable (97.5%). The study findings indicated that the independent variable was the predictor of acquisition of 21st century competencies among learners. The study recommended that supervision in schools should be intensified and appropriate support rendered to ensure effective and efficient implementation of the curriculum in order to help the curriculum fully achieve its objectives.