Objectives <p>The 10-item Child and Adolescent Mindfulness Measure (CAMM) is widely used to measure dispositional mindfulness among youth. Recognizing the need for brief tools to minimize time burden on participants and reduce study costs, the present study aimed to validate a short form of the CAMM (CAMM-5-FR), a 5-item derived version of the original 10-item version, among adolescents.</p> Method <p>A total of 1801 adolescents (42.5% girls) aged 14 to 18 years (mean = 14.73 years; standard deviation = 0.83 years) from six high schools completed the CAMM-5-FR and other measures to assess its construct validity. We analyzed the factor solution, psychometric properties, and gender invariance of the measure.</p> Results <p>The results of a confirmatory factor analysis supported the single-factor solution of the CAMM-5-FR. The scale showed adequate internal consistency, and no floor or ceiling effects. Construct validity was supported by positive correlations with measures of self-esteem and satisfaction with life (convergent validity), and negative correlations with alexithymia and internalizing&#xa0;symptoms (divergent validity). Participants who had experienced childhood maltreatment from their parents exhibited lower levels of mindfulness (known-groups validity). Additionally, measurement invariance indicated partial invariance (metric and scalar) of the scale between boys and girls.</p> Conclusions <p>Overall, the results suggest that the CAMM-5-FR is a promising screening tool for efficiently assessing dispositional mindfulness among adolescents.</p>