Purpose: The purpose of this paper is to contribute to the literature on student trust and to examine the relationship between student trust, behavior, and academic outcomes in high school. It asks, first, does trust have a positive effect on high school outcomes? Second, does trust influence student behavior, exerting an indirect effect on schooling outcomes? Third, are school size and student socioeconomic status (SES) antecedents of trust? Design/Methodology/Approach: A nationally representative sample of students attending public high schools in the USA (n = 10,585) is drawn from the Educational Longitudinal Study. Structural equation modeling is used to examine the relationship between student trust, behavior and high school outcomes, controlling for SES, school size and prior achievement. Multiple measures of academic achievement are considered. Findings: There is a significant relationship between student trust, behavior and high school outcomes. Students who trust have fewer behavioral incidents and better academic outcomes with results suggesting that trust functions through behavior. This is true regardless of SES, school size or prior achievement. Practical Implications: School leaders cannot change parental income or education, but can build trust. Developing and attending to student trust may not only mean that students are better behaved but, more importantly, are more successful academically. Social Implications: In spite of decades of policy and legislation intended to improve schools, closing the achievement gap has proven elusive. One reason may be the relentless focus on physical artifacts of schooling, such as school organization, curriculum, testing and accountability, and a concomitant lack of attention to sociocognitive factors key to learning. Schools are social systems, and high levels of learning are unlikely to occur without a nurturing environment that includes trust. Originality/Value: This research makes a valuable contribution by focussing on student trust in high schools and by illuminating the relationship between trust, behavior, and academic outcomes. Results suggest that trust impacts a broad range of high school outcomes but functions indirectly through behavior.