Adaptability is defined as appropriate cognitive, behavioral, and/or affective adjustment in the face of uncertainty and novelty. Building on prior measurement work demonstrating the psychometric properties of an adaptability construct, the present study investigates dispositional predictors (personality, implicit theories) of adaptability, and the role of adaptability in predicting academic (motivation, engagement, disengagement) and non-academic (self-esteem, life satisfaction, sense of meaning and purpose, emotional instability) outcomes. This longitudinal study (2 time points, 1 year apart), involving 969 adolescents from 9 high schools, found that personality (conscientiousness and agreeableness--positively; neuroticism--negatively) and implicit theories (effort-related beliefs about intelligence--positively) significantly predicted adaptability (beyond the effects of socio-demographics and prior achievement). Further, adaptability significantly predicted academic (class participation, school enjoyment, and positive academic intentions--positively; self-handicapping and disengagement--negatively) and non-academic (self-esteem, life satisfaction, and sense of meaning and purpose--positively) outcomes beyond the effects of socio-demographic factors, prior achievement, personality, implicit theories, and 2 cognate correlates (buoyancy and self-regulation). These findings hold implications for researchers and practitioners seeking to understand and address young people's responses to their changing academic and non-academic worlds.