Background: Emotional development in individuals with intellectual disabilities follows distinct trajectories; however, few psychometrically-sound tools target this dimension. Aims: This study examined the psychometric properties of the French version of the Scale of Emotional Development-Short (SED-S) in youth and adults with intellectual disabilities. Methods: A multicentre cohort of 170 participants with mild-to-profound intellectual disabilities was assessed. Internal consistency (McDonald’s ω) and inter-rater reliability (intraclass correlation coefficient, ICC) were evaluated. Construct validity was tested using confirmatory factor analysis. Associations with intellectual disabilities severity, adaptive functioning, and age were explored using correlations and nonparametric tests. Results: The SED-S demonstrated high internal consistency (ω = 0.933) and strong inter-rater reliability (ICC = 0.851). A one-factor model supported construct validity. SED-S scores were significantly related to intellectual disability severity and autism spectrum disorder diagnosis but not age. Conclusion: The French SED-S is a reliable and valid tool for assessing emotional development in French-speaking individuals with intellectual disabilities.