Adolescence is an increasingly vulnerable period for the onset of affective disorders and
other mental health issues that can significantly impact an individual’s subjective well-being. This
study aims to examine the relationship between emotional intelligence (ability EI), measured with
a performance-based instrument, and Subjective Happiness in adolescents. It also explores the
mediating role of positive (PA) and negative affect (NA) in this association and the moderating role of
gender. The sample consisted of 333 first-year secondary school students from five centers in Spain,
with an average age of 12.11 years (SD = 0.64), ranging from 11–14 years. Path analysis revealed an
indirect effect (through NA and PA jointly) of Total Ability EI on Subjective Happiness and a positive
direct effect that was observed only in females. Furthermore, this association was explored through
various branches of ability EI. The results of this study suggest that interventions aimed at improving
emotional abilities in adolescents while modulating the intensity of their emotions could significantly
impact their overall well-being.