This paper describes the development of a Japanese version of the Five Facet Mindfulness Questionnaire (FFMQ), currently the most comprehensive measure of mindfulness. This measure was derived using a joint factor analysis of five pre-existing measures. Evaluation of a Japanese version using a large sample of Japanese college students (total N = 1,349; mean age = 19.26, SD = 2.86, range = 18–63, 58% women) revealed preliminary evidence of sound psychometric properties. Exploratory and confirmatory factor analyses supported the measure’s original five-factor structure: observing, describing, acting with awareness, nonjudging, and nonreactivity. In addition, a hierarchical factor structure was found, with a second-order factor of mindfulness being related to four of the five specific factors (observing was the exception). This factor structure is consistent with previous findings from a sample unselected for meditation experience. All five subscales (facets) and the total score had acceptable to good internal consistency. Construct validity was demonstrated via expected correlations with related measures. Mindfulness facets were generally positively associated with adaptive psychological functioning. Specific correlates did differ across the five facets, providing further support for the multidimensional nature of mindfulness. The correlates of observing facet were suggestive of more maladaptive outcomes, replicating results obtained with unselected and nonmeditating samples. Overall, the Japanese version of the FFMQ appears to have psychometric properties comparable to those of the original version, warranting its use in future studies.