This quantitative predictive study investigated the intricate dynamics of the Imposter Phenomenon (IP) among online doctoral students, exploring its impact on Student Belongingness (SB) and Self-efficacy (SE). Findings revealed a significant negative association between higher IP scores and decreased SE, highlighting the imperative to address IP for enhancing online doctoral students' confidence. The link between IP and SB is less direct, with factors like race influencing students' sense of belongingness. The study underscores the need for tailored interventions to tackle IP challenges and foster an inclusive online learning environment, particularly for diverse doctoral student populations. Understanding the nuanced interplay between IP, Belongingness, and SE contributes valuable insights to guide strategies promoting a supportive and empowering experience for online doctoral students. [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.]