The performance of the Chemistry in Kenya Certificate Secondary Education (KCSE) national examination has been reported to be on a downward trend because of the several factors affect the teaching and learning of Chemistry.The purpose of the study was to analyze the effects of teaching methodologies on students’ academic performance in chemistry in public secondary schools in Ngong Sub-County, Kajiado County, Kenya.The study was guided by these objectives: To determine the teaching methods used in teaching chemistry in Public Secondary Schools in Ngong Sub-County, Kajiado County.To analyze the factors that influences the choice of teaching method in Chemistry subject among the teachers in Public Secondary Schools in Ngong Sub-County, Kajiado County.To examine the extent to which teaching methods influence the Academic Performance in chemistry in Public Secondary Schools in Ngong Sub-County, Kajiado County.The study was grounded on Albert Bandura’s theory ofSocial Learning theory.A descriptive survey research design was used, and a quantitative approach was adopted during data analysis. The study used 129 participants, which were comprised of 114 forms two and three students and 15 teachers, drawn from public secondary schools in Ngong Sub-County, Kajiado. Statistical Package for Social Science (SPSS version 28) was used to analyze the data collected from the target population. About 76% of the results of this study indicated that the teaching and learning of Chemistry depended on the availability of the teaching and learning resources in the school and the presence of the laboratory technicians. From the findings, 60% showed that students’attitude was of great importance on the teaching and learning of Chemistry. The study recommends that students should be encouraged to develop positive attitudes towards chemistry subjects. Chemistry teachers should use modern methods of teaching, such as the use of computers, to motivate and sustain students' interest in chemistry. Chemistry teachers should organize motivational talks that would help to alleviate the negative attitude towards chemistry among students. The study also recommended that parents should support their children by buying learning and study materials required by the students. The school administration should provide adequate learning materials, adequate physical facilities, and modern learning equipment such as computers and projectors for the lessons encourage teachers to use charts when teaching some complex topics.