Youth sport participation is a source of well-being for adolescents, yet experiences vary and attrition can be high during this period. We sought to better understand the coach behaviours that foster positive experiences in youth sport by examining relationships between the motivational climate and athlete engagement (viz. confidence, dedication, enthusiasm and vigor). We reasoned that a mastery climate (emphasis on effort and learning) would correspond with higher athlete engagement. By contrast, a performance climate (emphasis on ability and outcome) was expected to correspond with lower athlete engagement. Two-hundred and sixty adolescent youth soccer players completed measures of athlete engagement and perceived coach motivational climate. All dimensions of athlete engagement were positively predicted by a mastery climate. In addition, cognitive aspects of athlete engagement were positively predicted by a performance climate. Canonical correlation analyses further indicated that a linear composite of athlete engagement was positively associated with a mastery climate. The findings suggest that the motivational climate is associated with engagement and a mastery climate offers a means of promoting higher levels of overall engagement.