This study aimed to investigate the predictive power of aspects of the romantic relationship on subjective well-being, beyond what is explained by sociodemographic and personality variables. Participants were 490 heterosexual adults (68.8% women), all involved in a monogamous romantic relationship. Romantic relationship variables were substantial predictors of the three components of subjective well-being, explaining 21% of the variance in life satisfaction, 19% of the variance in positive affect, and 15% of the variance in negative affect, in addition to sociodemographic variables and personality factors. Still, relationship satisfaction was one of the main predictors of subjective well-being. The results highlight the importance of romantic relationships over subjective well-being, suggesting that cultivating satisfying romantic relationships contributes to a happier life.