Background: People with autism spectrum disorder (ASD) face many psychosocial challenges throughout life, highlighting the need for programs and resources promoting psychosocial wellbeing. Indigenous peoples with ASD and/or other neurodevelopmental disorders must overcome cultural and social barriers to access such supports. This study aimed to identify psychosocial programs and resources developed world-wide for this population by systematically reviewing research evaluating programs aiming to promote the psychosocial wellbeing of this population and/or their caregivers; and collating and reviewing resources developed to promote their psychosocial wellbeing. Methods: Searches were last conducted in December 2019. The systematic review searched 28 electronic databases, and 25 electronic databases were searched for resources promoting psychosocial wellbeing. Additional published and unpublished studies were identified from relevant reviews, authors of eligible articles, and experts working in Indigenous Health. Articles and resources were screened for inclusion using pre-defined criteria. Articles included in the systematic review were assessed for quality using the Mixed Methods Assessment Tool. The diversity and paucity of outcomes reported precluded pooling of study findings for meta-analysis. Results: Seven articles situated in the USA (2), Canada (3) and Australia (2); and eleven resources developed in Australia (9), Canada (1) and New Zealand (1) met inclusion criteria. All articles showed some promising findings for improving psychosocial wellbeing for Indigenous children with ASD and/or another neurodevelopmental disorder, and 5 of 7 evaluated the cultural adaptation of an existing evidence-based program for an Indigenous population. However, methodological quality was moderate or low (57% and 43% of articles respectively) and no studies had adult participants. The psychosocial wellbeing supports provided by the 11 resources included psychoeducation, community support, and services/workshops. Conclusions: Despite the paucity of research and resources found, important exemplars demonstrate that existing programs can be adapted to support Indigenous people with ASD and other neurodevelopmental disorders. While future policy should endeavour to facilitate Indigenous people's access to support services, and encourage researchers to develop and evaluate programs promoting psychosocial wellbeing for this population, given complexities of designing and evaluating new programs, careful and appropriate cultural adaptations of existing evidence-based programs would increase feasibility of ongoing research without compromising outcomes.