This study examined the relationship between salivary melatonin levels and interoceptive awareness in humans.We recruited 75 participants aged 18-55 years and measured their salivary melatonin concentrations using an enzyme immunoassay and their interoceptive awareness using the scores of the Multidimensional Assessment of Interoceptive Awareness (MAIA) scale.Melatonin levels negatively correlated with total interoceptive awareness scores. On the subscales, melatonin levels were negatively correlated with noticing, attention regulation, emotional awareness, self-regulation, body listening, and trust, and were positively correlated with not-distracting; however, there was no correlation with not-worrying.Individuals with high melatonin levels are unlikely to be aware of their bodily sensations and emotional states or to regulate attention and emotions; however, they appear to have a calm mind.