The present pandemic has affected psychological well-being in all areas, but in adolescent athletes, its impact is unknown. The objective of the present research is to determine the perceived psychological well-being, subjective vitality and mental strength of confined Mexican adolescent athletes depending on: sex, age and type of sport, as well as the predictive role of different variables evaluated in the perceived psychological well-being of athletes. 522 high level athletes, 280 men and 242 women, 16 +/- 1y, were administered the Psychological Well-being Scale for Adolescents (BIEPS-J), the Subjective Vitality Scale, and the translation of the Mental Toughness Inventory (MTI). The results showed that 15% of the athletes perceived low psychological well-being, self-acceptance was the most damaged dimension Males showed better perceived psychological well-being, increased vitality and in mental strength (p = 0.003, p = 0.001; p = 0.003). The variables included in the model that best explained the high and low levels of well-being were mental toughness (37%). It is suggested that third generation positive interventions will be implemented in sports care programs after confinement. Furthermore, we consider it necessary to continue exploring variables that can predict the psychological well-being.