ObjectiveGross motor competence is essential for daily life functioning and participation in physical activities. Prevalence of gross motor competence in children with intellectual disabilities (ID) and/or autism is unclear. This systematic review aimed to identify appropriate assessments for children with ID and/or autism.Design & data sourcesAn electronic literature search was conducted using the EBSCOhost platform searching MEDLINE, Education Research Complete, ERIC, CINAHL Plus and SPORTDiscus databases.Eligibility criteriaIncluded studies sampled children with ID and/or autism aged between 1 and 18 yrs, used field-based gross motor competence assessments, reported measurement properties, and were published in English. The utility of assessments were appraised for validity, reliability, responsiveness and feasibility.ResultsThe initial search produced 3182 results, with 291 full text articles screened. 13 articles including 10 assessments of motor competence were included in this systematic review. There was limited reporting across measurement properties, mostly for responsiveness and some aspects of validity. The Bruininks–Oseretsky Test of Motor Proficiency-2 followed by The Test of Gross Motor Development-2 demonstrated the greatest levels of evidence for validity and reliability. Feasibility results were varied, most instruments required little additional equipment (n=8) and were suitable for a school setting, but, additional training (n=7) was needed to score and interpret the results.ConclusionThis review found the BOT-2 followed by the TGMD-2 to be the most psychometrically appropriate motor competency assessments for children with ID and/or autism in field-based settings. Motor competence assessment research is limited for these cohorts and more research is needed.PROSPERO registration numberCRD42019129464.