Background: It is necessary to understand which variables successfully contribute to the adoption of positive behaviour support (PBS) in disability services if people with disability are to experience meaningful outcomes. Methods: A systematic review of the disability support literature was undertaken, and meta-aggregation was used to synthesise the findings. The study applies ENTREQ statement criteria, and diffusion of innovations theory was used to analyse and interpret the results. Results: Twenty-seven papers were included in the analysis, from which over 300 findings were extracted. Forty-one aggregated findings generated a final set of 26 principles which informed the development of a conceptual framework for the adoption of PBS in disability services. Conclusion: The conceptual framework and supporting principles will assist those interested in introducing PBS into disability services for successful adoption and are applicable to researchers, managers, and practitioners alike. Recommendations are made to expand research on the application of PBS in specific disability contexts and to broaden the application of PBS beyond challenging behaviour.