Simple SummaryExecutive functions are cognitive processing skills associated with planning, problem-solving, decision making, and regulating behaviour. For some individuals these abilities may be impaired, which can have negative long-term impacts. It has been proposed that interacting with animals may provide an opportunity to strengthen these skills. A systematic review was carried out to assess the ways in which interacting with animals may improve executive functions. This review included 23 studies exploring executive functions across three contexts: the human–pet relationship, the presence of an animal, and involvement in an animal-assisted service. There is some evidence to suggest that interacting with an animal may be beneficial for older adults, whilst horseback riding seems particularly beneficial for children; however, the overall methodological rigour is limited.AbstractThere has been growing interest in the potential benefits of using human–animal interactions to improve executive functions: cognitive processes that allow individuals to plan, solve problems, and self-regulate behaviour. To date, no comprehensive review has been conducted. The purpose of this study was to evaluate existing literature, adopting broad inclusion criteria. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 16 papers were identified from peer-reviewed literature. Additional papers were identified from grey literature, including 6 dissertations and 1 thesis. A review of these 23 studies found that human–animal interactions and executive functions are investigated in three main ways: (1) exploring the potential benefits of the human–pet relationship, (2) exploring the impact of an animal’s presence during administration of executive function tests, and (3) evaluating the efficacy of animal-assisted services (e.g., animal-assisted therapy) on executive functions. Five of the included studies reported a significant improvement across all measured domains of executive functions, but effect sizes were underreported. Comparatively, 9 studies reported mixed findings,d= 0.32–0.55, while 8 studies reported no significant results. The overall rigour of the research was limited, with great heterogeneity between the study methodologies and outcome measures used. It is recommended that future studies utilise high-quality research methodologies through the use of randomisation, pre- and postmeasures, and appropriate control conditions, where possible.