It is an undisputed fact that reading remains one of the most central skills in the success of any educational pursuit. This study titled "Effects of Schema Theory on Junior Secondary School English Learners? Performance in Reading Comprehension in Zaria Educational Zone" was conducted to find out the effects of schema theory on the reading comprehension of JSS 2 students. Three specific objectives, research questions and hypotheses were formulated. A reading comprehension test was administered to the students comprising an experimental and control groups. The population for the study was the 32 public schools in Zaria Local Government Area of Kaduna State from which two schools were selected (Government Junior Secondary School, Gyallesu and Government Junior Secondary School, Aminu). Samples of 120 students were selected from both schools using purposive and random sampling technique. The students were given a pre-test before they were taught using schema theory techniques after which a post-test was administered. The data collected were analyzed using inferential statistics and was used to answer the research questions and the hypotheses for the study. In all, the research questions raised showed that schema theory was effective for junior secondary school English learners performance in reading for literal, inferential and critical interpretation and evaluation comprehension, Thus, based on these findings, it is recommended that schema theory should be the primary mode in teaching reading comprehension. Similarly, English language teachers should take advantage of the schema theory technique for developing junior secondary school student reading comprehension ability. Finally, areas for further research in the related field was suggested