Contemporary models emphasize linkages between malleable positive psychological orientations and enhanced quality of life. As such, it is important to consider if these positive orientations provide unique explanatory power beyond the long-established relations between quality of life and within-person, less malleable personality traits. This study contributed to the literature by examining the relations among adolescents' personality traits, positive psychology orientations, and self-reported quality of life indicators. These relations were further examined by considering the mediating effects of the important contextual influences of school connectedness. Self-report responses of 1,867 California high school students to an 88-item schoolwide online survey that included the Big Five Inventory-10 (Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness), the Social Emotional Health Survey-Secondary (Belief in Self, Belief in Others, Emotional Competence, and Engaged Living), the School Connectedness Scale, the Brief Multidimensional Life Satisfaction Scale, and the Social Emotional Distress Scale--Secondary were used to examine relations. Stepwise multiple regression analyses showed that after controlling for demographic variables (Block 1: sex, grade, and ethnicity) the personality traits (Block 2) were, as expected, significantly associated with life satisfaction and emotional distress. Supporting study hypotheses, the inclusion of positive psychological orientations (Block 3) explained significantly more variance of students' life satisfaction (Delta R[superscript 2] = 26%) and emotional distress (Delta R[superscript 2] = 5%). Mediation analyses using Structural Equation Modeling (SEM) found that only positive psychological orientations had significant indirect relations with quality of life through school connectedness. Implications and future research and practice are discussed. [This is the online version of an article published in "Child Indicator Research."]