The study examined the availability and utilization of educational facilities and academic achievement of public secondary school students in Lagos State, Nigeria. Eight research questions and six null hypotheses guided the study. The study is a correlational survey adopting the ex-post-facto research design method. The population of the study was 19982 comprising all the 676 Principals of the public secondary schools, 1352 Vice Principals, and 17954 teachers from the six Education Districts of Lagos State. The cluster and simple random sampling technique was used to obtain a sample size of 999 secondary school teachers, vice principals and principals for the study. Two self-developed instruments, the checklist and SS2 promotion examination results were used to collect data for this study. The validity of the instrument was established through face and content validity. Reliability for the availability and utilization of educational facilities checklist was tested using the test, retest method. The test yielded a coefficient of 0.82, data collected from the field was presented in tables and analyzed using the statistical tools of percentage, mean, and standard deviation to answer the research questions. Items with mean value of less than 2.50 were rejected. To test the hypotheses, the Pearson moment correlation coefficient (r) method was used, acceptance decision was determined at 0.05 level of significance. The extent of availability of educational facilities for academic achievement of public secondary school students in Lagos was high; The extent of utilization of educational facilities for academic achievement was high and there is a significant correlation between the availability and utilization of educational facilities and students’ academic achievement of Public Secondary School Students in Lagos State. Based on the findings, it was recommended that training should be organized for teachers and students on the benefits of utilizing available resources effectively. Government should implement a system for regularly assessing the conditions and functionality of educational facilities, this will help to identify areas of improvement ensuring that available facilities are well maintained for their optimal utilization for students’ academic achievement.