To draw valid and reliable conclusions from child studies involving facial expressions, well-controlled and validated (child) facial stimuli are necessary. The current study is the first to validate the facial emotional expressions of child models in school-aged children. In this study, we validated the Radboud Faces Database child models in a large sample of children (N = 547; 256 boys) aged between 8 and 12. In addition, associated validation measures such as valence, clarity, and model attractiveness were examined. Overall, the results indicated that children were able to accurately identify the emotional expressions on the child faces in approximately 70% of the cases. The highest accuracy rates were found for "happiness," whereas "contempt" received the lowest accuracy scores. Children confused the emotions "fear" and "surprise," and the emotions "contempt" and "neutral" with one another. Ratings of all facial stimuli are available (https://osf.io/7srgw/) and can be used to select appropriate stimuli to investigate the processing of children's facial emotional expressions.