In this study, we sought to locate the three traits known as the temperamental basis of humor (cheerfulness, seriousness, and bad mood) in the personality space defined by the five-factor model in adolescents. The study also investigated the relative contribution of these narrower traits – in comparison to broad personality traits – to explaining variance in relevant outcomes: the frequency of humor behaviors and well-being. A sample of N = 379 adolescents aged 10 to 17 years (mean age = 15.52, 28.5% male) completed questionnaires on the traits of cheerfulness, seriousness, and bad mood (STCI-youth), the personality traits of the five-factor model (IPIP-junior), the frequency with which they typically displayed 13 different humor behaviors (HUMOR), and well-being (PWI-SC). The results reveal that all three traits assessed by the STCI-youth predicted unique variance in both the frequency of humor behaviors and well-being – beyond demographic variables, the personality traits of the five-factor model, and each other. Using dominance analysis, we demonstrate that the variables assessed by the STCI-youth – in particular, cheerfulness and seriousness for humor behaviors and cheerfulness and bad mood for well-being – outperform broad personality traits in accounting for the variance in humor behaviors. In conclusion, the present study shows that cheerfulness, seriousness, and bad mood overlap with broad personality traits, while being unique predictors of everyday humor behaviors and well-being. Thus, they are well-suited for investigating individual differences in the domain of humor among adolescents.