The study determined the relationship among extroversion, introversion and academic performance of senior secondary school students, Sabon Gari, Zaria, Kaduna State. Correlational design was used for this study. Three objectives were raised, research questions, and null hypotheses were in line with the objectives. The population of the study was 1487 SS II students, proportional sampling technique was employed in selecting three hundred and fifty (350) SS II students from six selected senior secondary schools in Sabon Gari, Zaria, Kaduna State. Eysenck Personality Inventory was adapted to collect data for this study, objectives test in Mathematic and English was constructed to collect data on academic performance. The biodata were analyzed using frequency count and simple percentage, means and standard deviation were used to answer the research questions. Pearson Product Moment Correlation Statistic was used to test the null hypotheses one and two, while hypothesis three was tested using t-test. The results showed that, there is no significant relationship between extroversion and academic performance (r=.057, p=.235). However, introversion is correlated with academic performance (r=-.123, p=.047). There is significant difference between academic performance of extrovert and introvert students (t-cal = 50.195). From these findings, discussion was made and the researcher recommended that, extroverted students should be counselled on how to reduce social activities and pay more attention to their academics in order to improve their performance.