Introduction Systematic reviews and metanalyses have shown that mindfulness-based interventions can have positive effects on health, such as reducing anxiety, depression, and chronic pain. However, their effect on sleep-related outcomes is not yet well established. Sleep can be assessed subjectively (questionnaires, sleep logs, self-reporting) and/or objectively (actigraphy, polysomnography, biological markers), and outcomes may differ depending on which type of assessment is used.