The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a hybrid validation approach was taken, using the limited data available from both isolated and full body impact data. A child human body model was first developed through scaling of a 50th percentile male human body model to the average 6-year-old child anthropometry, i.e. the focus of this study. Regional validation simulations were performed investigating the neck, thorax and abdomen. Simultaneously, two simulation environments were developed, replicating experimental test scenarios where child anthropometric test devices (ATD) were subjected to frontal impacts. A numerical ATD model was used to simulate the impacts in order to validate the numerical test environment. The simulation environment was then used to replicate child cadaver tests for validation of the child human body models. Three subject specific child human body models were created showing comparable acceleration and trajectory responses to the experiments when subjected to the frontal impact. The models provide a useful tool for simulating child frontal impact scenarios that could facilitate further sensitivity and optimization studies. Furthermore, the methods used to develop them represent a useful methodology for validating child human body models where more in depth biomechanical data is unavailable.