Available research discusses the first-generation undergraduate experience, graduate students' sense of belonging, and first-generation graduate students, but little research shows the themes that impact a first-generation graduate student's sense of belonging. Understanding the first-generation graduate students' experience as a marginalized group allows higher education practitioners to create a more inclusive environment to aid their belonging. This qualitative, instrumental case study, guided by College Student Sense of Belonging theory, was focused on ten first-generation graduate students' sense of belonging within their doctoral program. Four of the seven core elements presented in this theory emerged as salient to first-generation graduate students' sense of belonging. The four core elements representative of their experience concerning belonging within their doctoral program were: context/time/factor determines importance, mattering, influenced by one's identity, and leads to positive outcomes/successes. A few examples of themes that participants shared as being salient to their first-generation identity included the need for faculty validation, being seen by others, first-generation identity barriers, and faculty outreach. The results of this study provide many practical applications and academic tools to create an inclusive approach that aids first-generation graduate students in their sense of belonging. [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.]