Love is a complex construct of undeniable importance for human beings and an area of research that has progressed over the past decades. The capacity to love, specifically, refers to the capacity for involvement, investment, and maintenance of a committed romantic relationship, resulting from complex developmental processes that begin in childhood and continue to be shaped throughout development. Despite its relevance, there is still little evidence of its relationships with indicators of positive human functioning. This study examines the link between the capacity to love and emotional, psychological, and social well-being. Furthermore, it delves into potential differences in the capacity to love based on life cycle stages (emerging adulthood and midlife) and gender. The research involved 535 participants, with 282 (52.7%) falling under the emerging adulthood category (18–25 years) and 253 (47.3%) classified as middle-aged adults (45–65 years). Multivariate variance analyses indicate emerging adults demonstrate a greater capacity to love in all dimensions except acceptance of loss, grief, and jealousy. Concerning gender, there were no significant differences. Prediction models indicate that age and acceptance of loss and grief are significant and positive predictors of all types of well-being, and basic trust is a significant and positive predictor of emotional well-being. Overall, this research sheds light on the vital role the capacity to love plays in human well-being and emphasizes the need for interventions that focus on nurturing and developing this aspect of human relationships.