Housing affordability has become one of the most pressing socioeconomic challenges in the United States, with significant implications for poverty, inequality, economic mobility, and urban development. This study examines the relationships among demographic inequality, housing affordability, and urban socioeconomic outcomes using evidence synthesized from the American Community Survey (ACS), Decennial Census, HUD Housing Data, Opportunity Atlas, and the Federal Housing Finance Agency House Price Index (FHFA-HPI). A systematic review and secondary data synthesis approach was employed to evaluate changes in housing affordability since 2010, the links between poverty and housing burden, demographic disparities in housing outcomes, the influence of educational attainment, and the effectiveness of major housing policy interventions. Findings indicate a marked decline in housing affordability, driven by housing prices and rents increasing substantially faster than household incomes. Low-income households experience disproportionately high levels of housing cost burden, demonstrating a strong inverse relationship between income and affordability. Significant disparities persist across demographic groups, with African American, Hispanic, Native American, female-headed, and young adult households facing the greatest affordability challenges. Higher educational attainment is consistently associated with improved housing outcomes, including higher homeownership rates, lower housing cost burdens, greater incomes, and increased access to high-opportunity neighborhoods. Among policy interventions, Housing Choice Vouchers, the Low-Income Housing Tax Credit (LIHTC), Community Land Trusts, and Transit-Oriented Development initiatives show the greatest effectiveness in improving affordability and promoting equity. The study concludes that housing affordability is a fundamental determinant of socioeconomic well-being, wealth accumulation, and intergenerational mobility, requiring integrated policies that expand affordable housing, strengthen housing assistance, promote educational and economic opportunity, and reduce structural inequalities affecting vulnerable populations.