This study proposes two links between facets of mindfulness and different forms of humor: First, the common benevolence should link mindfulness positively to light forms of humor and negatively to darker forms of humor. Second, similar cognitive mechanisms should underlie both mindfulness and humor ability (humor detection, comprehension, and production). Third, both are malleable, and we hypothesize that fostering humor and mindfulness may mutually influence each other, leading to innovative and practical interventions for settings such as the workplace. In three studies, the relationship of humor and mindfulness as outlined in the Humor Mindfulness Relationship Model was investigated. In Studies 1 and 2, the relationship of different forms of humor and mindfulness was investigated in a sample of health care professionals and a broad online sample. In Study 3, the effect of a mindfulness intervention on humor as a character strength was investigated, giving preliminary insights into the mutual malleability of both. Results confirmed the positive relationship among light forms of humor and mindfulness as well as negative relationships of darker forms of humor with mindfulness. The mindfulness intervention fostered humor as a character strength. These results indicate that humor and mindfulness may be fruitfully combined in positive interventions as well as in the vocational setting. Moreover, the results suggest initial evidence for the Humor Mindfulness Relationship Model.