Autism is a developmental condition that affects motor skill development. There is a lack of comprehensive research exploring the potential benefits of extended reality (XR) technologies, including virtual reality (VR) and augmented reality (AR), for improving motor skills in autistic children. This systematic literature review (SLR) addresses this research gap by investigating XR-based interventions targeting motor skill development in autistic children. The SLR analysed 15 primary studies published between 2012 and 2024, examining the use of VR and AR to improve motor skill development in autistic children. The interventions ranged from one session to 12 weeks, lasting 12 to 45 minutes, and targeted various body movements. XR platforms and devices used included VR headsets, motion capture systems, and exercise bikes. Recurrent neural networks, dynamic difficulty adjustment, and behaviour trees were employed to enhance intervention dynamics and extract valuable insights from collected data. The results suggest that using XR interventions has significant potential to improve physical activity levels and motor skills development among autistic children. However, the research designs varied, with only one study including their intervention framework’s generalisation and maintenance phases. This study offers an encouraging avenue for future research and intervention design in this field.