Objectives <p>A scale measuring students’ attention regulation in classroom contexts has not yet been developed. This research developed and validated the classroom mindful attention regulation scale (CMARS) using modern psychometric approaches for Bangladeshi emerging adults.</p> Method <p>A convenience sample of 600 university students aged 18–25&#xa0;years was recruited. Measures completed by the participants include CMARS, Mindful Attention Awareness Scale, Philadelphia Mindfulness Scale, and Depression Anxiety Stress Scale-21. To examine the factor structure and ensure factor retention, an exploratory factor analysis (EFA) and parallel analysis (PA) were run, respectively. To validate the factor structure, confirmatory factor analysis (CFA) was performed. Cronbach’s alpha, McDonald’s omega, and Ferguson’s delta were used to determine the internal consistency reliabilities. Multi-group confirmatory factor analysis (MGCFA) was conducted to test the invariance across gender.</p> Results <p>Content validation resulted in the retention of 10 items. The two-factor structure emerged from the EFA, and this solution was retained through PA. While validating the factor structure, CFA model fit indices showed an adequate fit to the data. Mean inter-item correlations, corrected item-total correlations, and internal consistency reliabilities fall within the acceptable ranges. MGCFA revealed that the CMARS can invariably measure the mindful attention regulation across gender. The relationship of CMARS with depression, stress, and mindfulness components indicated the convergent validity of the measure.</p> Conclusions <p>Altogether, the CMARS has been found to be a valid instrument for assessing students’ classroom attention regulation skills and identifying areas for improvement.</p> Preregistration <p>This study is not preregistered.</p>