The current study aimed to find the relationship between personality traits and learning styles of English for Academic Purposes (EAP) students across high, intermediate, and low levels of reading proficiency in online courses. To this purpose, 50 male and 50 female BA students were selected through convenient sampling from the executive management department at Iran University of Science and Technology, Tehran, Iran. Their age range was 20 to 26 years. They were divided into three groups of high, intermediate, and low reading proficiency based on a simulated TOEFL CBT reading test. Their learning style and personality type were assessed through Myers-Briggs Type Indicator (MBTI)-Form M and the Learning Style Inventory-3 (LSI3), respectively. Upon collecting the data from the MBTI, the LSI3, and the reading tests, the researchers coded the scores and used path analysis. The results showed that there were significant relationships among a number of the variables under investigation; especially extroversion was found to be an important personality trait affecting online reading proficiency and other variables. The results also showed that the extroversion trait had a positive significant relationship with high reading proficiency, while the thinking dimension resulted in low reading proficiency. Moreover, The participants who had the objective experience trait possessed a high ability in reading, and those who had the reflective observation trait were less proficient in reading. تفاصيل المقالة