The well-being of young people is of considerable concern with many initiatives targeting the health behaviors of this population. Educators are among the professional groups being challenged to understand, evidence, and enhance childhood well-being. Working with a case study U.K. school adolescent subjective well-being (SWB) was examined through the administering of the Personal Wellbeing Index-School Children (PWI-SC; n = 840) and focus groups with pupils (n = 18). PWI-SC results suggest significant differences in personal well-being between school years (p < 0.001). Focus group data indicate that transitional periods associated with adolescence, feeling unsafe, and anxiety over the future were linked to a lowering of SWB. Asset-based well-being strategies that promote health literacy and build on the resources of young people and local communities are considered as a means for schools to promote well-being.