A significant academic achievement gap has existed for many decades between high- and low-income students in America's schools (Reardon & Portilla, 2016). Of the many solutions proposed to eliminate the poverty gap, early education has shown promising results (Connors, Morris, & Friedman-Krauss, 2015). Eliminating the achievement gap earlier in a child's life has more significant long-term positive effects. The purpose of this study was to explore the relationships between socioeconomic status and academic readiness as measured by the Desired Results Developmental Profile, California's developmental assessment for all students in state-run preschools. The DRDP measures development across eight separate domains: Approaches to Learning/Self-Regulation, Social and Emotional Development, Language and Literacy Development, Math and Science Cognition, Physical Development, History-Social Science, Visual and Performing Arts, and English Language Development. Using demographic data from 1,334 preschool students in San Diego County, California, this study performed correlational and multiple regression analysis to discover the statistical relationships between parent income and the DRDP test results for six domains available. Results of this analysis show the existence of the poverty gap in California's preschools. A significant relationship between income and DRDP test scores was found in all six domains, the strongest relationships occurring in language and literacy development and math cognition. Positive relationships between family income and DRDP domains more often occur in students who are Hispanic, female, and non-English learners. Conversely, negative relationships occur between family income and DRDP domains for White students. This study strengthens the argument for early education initiatives to help reduce the opportunity gap and also provides evidence for use of the DRDP to identify wider societal trends, such as achievement gaps. The specific findings may also be used by researchers as a starting point for further study and exploration into the poverty gap, its causes, effects, and potential solutions. [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/en-US/products/dissertations/individuals.shtml.]