Food forests are a type of agroforestry designed to mimic natural forests, aimed at being low maintenance, biologically sustainable, resilient to climate change and highly efficient. This study has estimated the carbon stock of the understorey in a well-established, 0.64 ha peri-urban food forest in Devon, UK. Through various field measurements and the use of 23 allometric equations, above-ground biomass (AGB) was calculated, and below-ground biomass (BGB) was estimated based on a root-to-shoot ratio of 0.26. The corresponding carbon stock was calculated based on carbon content analysis of shrub samples of 31 species. The understorey was estimated to store 3.69 Mg C ha⁻¹, corresponding to 8.54% of the total living carbon stock of 43.22 Mg C ha⁻¹ stored within the food forest of the Agroforestry Research Trust. This study demonstrates that the often-overlooked understorey constitutes a notable addition to the living biomass carbon stock especially in temperate food forests with dense understoreys.