Two cross-sectional studies were conducted to examine the relationships between gratitude and athletes' well-being. Study 1 examines the relationship between dispositional gratitude and well-being, while Study 2 investigates the relationship between sport-domain gratitude and well-being. In Study 1, 169 Taiwanese senior high school athletes (M = 16.43, SD = 0.7 years) were administered the Gratitude Questionnaire (GQ; McCullough et al. 2002, "Journal of Personality and Social Psychology", 82(1), 112-127), Team Satisfaction Scale (Walling et al. 1993, "Journal of Sport & Exercise Psychology", 15, 172-183), Satisfaction with Life Scale (SWLS; Diener et al. 1985, "Journal of Personality Assessment", 49, 71-75), and the Athlete Burnout Questionnaire (ABQ; Raedeke and Smith, 2001, "Journal of Sport & Exercise Psychology", 23(4), 281-306). In Study 2, a separate sample of 265 adolescent athletes (M = 16.47 years, SD = 0.7) were administered the modified Sport-domain GQ, Team Satisfaction Scale, and ABQ. Study 1 results showed that dispositional gratitude positively predicts team satisfaction and life satisfaction, and negatively predicts athlete burnout. Findings from Study 2 revealed that sport-domain gratitude positively predicts team satisfaction and negatively predicts athlete burnout. A stronger gratitude and well-being relationship was observed in Study 2. This research provides the initial verification that gratitude and adolescent athletes' well-being are related. Possible mechanism of this relation, limitations, and practical implications are discussed.