Adult learners, or undergraduate students aged 24 years or older, represent one third of the undergraduate student population in the United States. The purpose of this study was to explore the pathways to thriving for undergraduate adult learners, taking into consideration their entering characteristics and life circumstances. Thriving has been defined as student success that includes not only a student's academic performance and engagement but also their psychological well-being and interpersonal relationships. However, most undergraduate student success literature has focused on traditionally aged students, perpetuating a knowledge gap of what student characteristics and campus experiences are predictive of thriving among adult learners. Given the projected continuation in adult learner enrollment, this study addressed a gap in the student success literature by assessing the pathways to thriving for adult learners. Responses to the Adult Learner Thriving Quotient, an instrument that measures students' academic, social, and psychological well-being, were used to examine the pathways to thriving among 1,447 adult learners from 4-year institutions in the United States. Results indicated the structural model explained 89% of the variance in thriving among the adult learner participants. Psychological sense of community, spirituality, and satisfaction with one's living situation had the greatest direct effects on thriving. Faculty commitment to diverse students and perspectives had the greatest indirect effects, and the second greatest total effect on thriving among these adult learners. Implications of these findings include institutional leaders prioritizing development of a sense of community in adult programs to build interpersonal connections among adult learners, providing training and resources for faculty to enhance their commitment to inclusive pedagogy, and leveraging the strength of spirituality as meaning making to help adult learners thrive. This research informs institutional leaders how to support the overall wellness, student success, retention, and graduation of adult learners at their institution. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]