Background: Mindful eating is a concept that is increasingly being used to promote healthy eating. Observational studies have suggested associations with healthier eating behaviors, lower weight status, and favorable cardiovascular biomarkers. However, existing scales assessing mindful eating have some limitations. Our study aimed to develop and validate a scale assessing the level of mindful eating in a general population. Methods: The Mind-Eat Scale was developed in four main steps: 1. Generating an initial item pool covering all aspects of mindful eating; 2. Reviewing items with experts and naive individuals; 3. Administering the scale to a large and representative sample from the NutriNet-Santé cohort (N=3102); 4. Conducting psychometric analyses. Construct validity was assessed using exploratory (EFA) (N1=1302) and confirmatory (CFA) (N2=1302, N3=498) factor analyses. Content, discriminant, convergent, and divergent validity, internal consistency, and test-retest reliability were examined. Results: The initial pool of 95 items was refined to 24 items using EFA. The EFA highlighted six dimensions: Awareness, Non-reactivity, Openness, Gratitude, Non-judgement, and Hunger/Satiety, consisting of four items per dimension. CFAs showed a good fit for first and second-order models. Adequate content validity was confirmed. Discriminant, convergent, and divergent validity were supported by significant differences between subgroups of individuals, and correlations with eating behaviors and psychological well-being scales. The Mind-Eat Scale showed good reliability for all six dimensions, with high McDonald's ω and adequate intraclass correlation coefficients (ICC). Conclusions: This study validated the first tool assessing a total mindful eating score and its sub-dimensions in a general population. This scale can be an asset for clinical and epidemiological research on dietary behavior and related chronic diseases.