This dissertation examines relations between education-related self-beliefs and socioeconomic (SES)-based disparities in education. SES academic achievement gaps are a serious problem in the United States; however, they are not fully accounted for by objective family resources alone. I build from the premise that there is a subjective, psychological component as well; that young people's beliefs about themselves and their opportunities as students are differentially shaped by experiences of SES in school settings. Using a social comparison lens to integrate current psychological theories of self and identity with extant educational psychology, the two quantitative studies of this dissertation explore math self-beliefs direct and indirect role in SES-based academic achievement gaps. Study 1 explored how math self-concept and math self-efficacy interrelate with socioeconomic status (parental education and family income) and academic achievement (high school math GPA and college attendance). A series of seemingly unrelated generalized least squares regressions showed that, after adjusting for measures of ability and achievement, young people whose parents did not graduate college had significantly higher math self-beliefs. Family income mirrored this relationship when parental education was not included. Furthermore, Sobel-Goodman tests showed both math self-beliefs may work to indirectly uplift high school performance for young people without college educated parents. Study 2 complemented study 1 by focusing on socioeconomic inequality. With an overarching goal to capture SEI in a manner methodologically congruent with how it is discussed in current psychological theory, it examined objective measures of neighborhood inequality alongside young peoples' relative socioeconomic position. Seemingly unrelated regressions revealed significant higher family RSEP -- for both education and income -- predicted better math GPA above and beyond all measures of SES, SEI. Furthermore, mirroring the same pattern found in paper 1, some of the relationship between RSEP and math GPA was partially explained by young people's math self-concept such that lower relative position's negative association with GPA was significantly, albeit slightly, attenuated by higher math self-concept. [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.]