The primary aim of this study was to identify levels of fundamental movement skills (FMS) proficiency in primary school children. A secondary aim was to establish if these FMS proficiency levels differentiated between children born in different quartiles of the school year. The results demonstrated overall levels of FMS proficiency were low in both genders with significant differences in FMS proficiency established between genders on several of the skills. In addition, significant differences were shown with some FMS and quartiles of the school year in boys only. In summary, these findings suggest that there is a greater need for a clearer strategy or focus to promote and develop FMS proficiency within the primary school environment. It is also important, for PE teachers, and practitioners, to be aware of the effect of the RAE with FMS proficiency on development, assessment, and selection at this age.