Objectives: To undertake a realist review of carer‐led oral hygiene interventions for people with intellectual disabilities. This was run parallel with a Cochrane Review. Methods: Realist review methods were followed. This was characterized by an iterative process of developing and refining theories of how interventions might work, expressed as context‐mechanism‐outcome configurations. The steps included identifying candidate theories with local and international expert consultation before applying an iterative search strategy.