According to Gallup data, U.S. public school students increasingly endorse disengagement from school and hopelessness about the future. Over the years, research around student psychological ill-being has focused on it as a condition that students bring to school. Nevertheless, what is often omitted is the fact that the school environment also accounts for a significant amount of the frustration experienced by students in its environment. International research in sports and physical education has demonstrated that the proximal relational environment plays a pivotal role in determining outcomes of ill-being. However, there is currently no scholarship assessing the trajectory of influence of the general school environment on student ill-being in U.S. public schools. Therefore, as an extension of scholarship in such an understudied area of importance, this dissertation builds a line of inquiry around student psychological ill-being and related school social conditions. Using the framework of self-determination theory, this study conceptualizes student psychological ill-being and organizes its investigation in three stages. First, a foundation for the larger inquiry is established through the exploration of psychological ill-being operationalized as psychological need frustration. Secondly, this study conceptualizes a general school need thwarting environment by advancing a new measure and conducting a series of validation tests. Lastly, the study establishes need thwarting as a substantive predictor of student disengagement through the mediating role of need frustration.