The study focuses on the effect of gender inequality, teaching and learning environment on students' academic performance in Ogun State Junior Secondary Schools. The descriptive survey research design was adopted for the study. The population consisted of four-hundred students; stratified random sampling was used to select forty (40) public Secondary Schools on common culture, social and economic background in Ogun State. The research questions and five research hypotheses were used to guide the study. Questionnaire was employed to generate relevant data from the teachers on the academic performance of their students and the school teaching and learning environment. Data collected were analyzed using appropriate descriptive statistics as well as regression analysis, Pearson product moment correlation and t-test. All the postulated null hypotheses were tested for significant at 0.05 level of significance. The findings reveal among other things that, gender and learning environment jointly contributed significantly to the prediction of students' academic performance. Based on the findings, recommendation were made among other things that male and female students can be made to undergo the same educational programmes because academic performance is not really gender determined. Government should also provide good teaching and learning environment tend to be high where the teaching and learning environments is good and vise-versa.
Keywords: Gender, Inequality, Teaching, Learning, Environment.