Positive emotion regulation, that is, upregulating, maintaining, and savoring positive emotions, also bears the potential to counteract and thus mitigate negative affect. In this narrative review, we report on the social emotion of compassion as a particularly efficient form of positive emotion regulation. Compassion emerges as an affiliative response to the suffering of others. It is characterized by feelings of warmth and kindness and an initiation of prosocial caring behavior towards others. The inherent positivity of compassion is also in line with its related neural correlates. Compassion is associated with activity in the ventral striatum, the (subgenual) anterior cingulate cortex, and the orbitofrontal cortex, brain regions related to strong positive emotions, such as romantic and maternal love. In addition to its long tradition in Eastern philosophy, the practice of compassion has in recent years found its way into interventions in Western psychology, for example, within compassion-focused therapy. Recent findings confirm that affect-related mental training promoting compassion is also linked to functional and structural changes in neural networks associated with positive emotions and emotion regulation. This compassion-related plasticity in the neural systems of positive emotion regulation suggests that incorporating compassion into psychological interventions could prove to be a particularly effective way to support positive emotion regulation.