Online learning continues to be a growing frontier in higher education with increased demand and enrollments reported annually (Allen & Seaman, 2010, 2011). Discovering best practices and methods of instruction as well as assisting students in determining their highest possible level of success in this type of learning environment has been the focus of much recent research. This study investigates the relationship between success in an online academic environment and student personality type as assessed by the Myers-Briggs Type Indicator®. Specifically, the present research focused on the following research questions: (1) is one personality type more likely to enroll in an online course? (2) Is there a positive relationship between academic success (i.e., a passing grade) and a specific personality type? (3) Is there a positive relationship between academic failure (i.e., a failing grade) and a specific personality type? These questions are important to examine given the popularity of online learning because their answers help enable optimal fit between student and learning environment. The sample frame consisted of 1201 students from a variety of academic majors seeking to fulfill a degree requirement through a course offered in an online learning environment. The sample contained 102 students seeking degrees in eleven colleges in a large Midwestern university. Fifteen of the sixteen possible personality-type categories differentiated by the MBTI® were represented, and thirty-six online learning environments were exemplified. The results indicate the likelihood of enrollment did not differ by personality type; further, there was no positive relationship between academic success and one personality type. A relationship between academic failure and a given personality type could not be assessed due to the grade range restriction reported. No failing grades were indicated by participants. A post-hoc analysis using recursive partitioning did indicate several interesting breaks in the data by college and gender, which may prove useful for further analysis. Additional recommendations for future research are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]