Fundamental movement skills (FMS) are known as the building blocks required for participating in sport and physical activity. These skills encompass three categories of movement including locomotor, ball and balance skills. Children with ID (CwID) must be provided with opportunities to learn, practice and reinforce these skills. Throughout the literature, CwID exhibit lower motor skill proficiency levels compared to typically developing children (TDC). Phase one of this project involved completing a meta- analysis of studies comparing the FMS of CwID to TDC (n = 3525, age 4-12 years) in order to quantitatively obtain a macroscopic picture of the FMS proficiency of CwID in comparison with TDC. Phase two consisted of carrying out a nationwide assessment of a broad range of FMS amongst CwID (n = 100) and coaches’ perceptions of CwID proficiency levels participating in the Special Olympics Young Athletes (YA) programme. The main results highlight that CwID demonstrate low levels of FMS mastery (0-60.4%) TDC scored significantly higher in all FMS subsets compared to CwID (p < .001). Weak to moderate associations (0.20-0.59) were found on an individual skill level between CwID actual motor competence (MC) and coaches’ perceptions of children’s skill level. The final phase explored the experiences of coaches (n = 8) involved in delivering the YA programme, including their perceptions of the barriers and facilitators to implementing the programme. Overall, findings highlight sub optimal levels of FMS proficiency amongst CwID participating in the YA programme and the need for tailored FMS interventions targeting CwID specific weakness in FMS. Additionally, the results presented highlight a knowledge gap that exists in coach education. Training is required for YA coaches to 1) help them identify and correct weaknesses in FMS proficiency levels and 2) support them tailoring training programmes for CwID.