Online education is a relatively new manifestation in academia and as such, there are still many gaps in the knowledge of how to transfer face-to-face components of a classroom to the online platform. One of these gaps is how to encourage instructor-student relationships when the online platform is by nature anonymous. It can be difficult to foster relationships when the professor and students are faceless names, and this lack of relationship may impact student intent to leave a university. Therefore, it is important for universities to understand the dynamics of instructor social presence in a strictly online environment. The purpose of this correlational, non-experimental study was to examine the relationships between instructor social presence, student leader-member exchange (student-LMX), student engagement, learning management system quality, and student intent to leave his or her program of study prematurely. Descriptive statistics were determined using SmartPLS statistical software. SmartPLS structural equation modeling was also used to perform bivariate and mediation regression analysis and to test overall model fit. The sample included 206 undergraduate students attending online primarily freshman, sophomore, and junior level courses at a 100% online university. All bivariate and specific mediation test hypotheses were significant at p<0.05. The overall model, however, indicated student engagement to be a strong mediator, and this attenuated the mediation effect of the other mediators tested in the model including student-leader member exchange. This study is significant because it demonstrates that student engagement serves as a strong mediator between instructor social presence and student intent to leave a university more so than the mediating effect of student-LMX. Also, instructor social presence is strongly related to other important variables that predict student success. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]