This review aims to summarise existing research on the forest-based pedagogical approach known as forest school, as developed in the UK. Modelled on the nature kindergartens of northern Europe, forest school is popular in the UK and is now being practiced or explored in other countries around the world. Drawing on papers specifically researching forest school, identified through the Scopus database, it identifies and reviews key themes emerging from the literature: research on its development, relationship to classroom teaching and the national curriculum, impact on children’s development, and their relationship to the environment and environmental behaviour. It identifies the challenges and tensions emerging in the practice of forest school, between the performative agenda of schools and the alternative learning approaches embedded in forest school praxis. It summarises the attempts by several authors to develop theoretical models of forest school. It discusses the transferability of this forest education practice to new cultures, environments and educational systems. Finally, it concludes by identifying challenges for further research.