Despite extensive research, policies, and practical efforts to improve college readiness in the United States, a large proportion of low-income students remain unprepared to enter and succeed in higher education. This issue draws on the human ecology theory of Urie Bronfenbrenner (1917 2005) to offer a fresh perspective that accounts for the complexity of the interacting personal, organizational, and societal factors in play. Ecological principles shift the focus to individual differences in the ways that students engage environments and to the connections across students immediate settings and relationships. Viewing college readiness within an ecological system also reveals how the settings where development occurs are in turn shaped by more distant environments. The aspirations and behaviors that affect students college preparation originate in opportunities, resources, and hazards beyond their immediate environments. The ecological lens illuminates the need for coordinated, comprehensive efforts that affect students across the various levels of their environment and provides a framework for advancing college readiness research, policy, and educational practice. This is the 5th issue of the 38th volume of the Jossey-Bass series ASHE Higher Education Report. Each monograph is the definitive analysis of a tough higher education issue, based on thorough research of pertinent literature and institutional experiences. Topics are identified by a national survey. Noted practitioners and scholars are then commissioned to write the reports, with experts providing critical reviews of each manuscript before publication.