Mangrove soils represent a large sink for otherwise rapidly recycled carbon (C). However, widespread deforestation threatens the preservation of this important C stock. It is therefore imperative that global patterns in mangrove soil C stocks and their susceptibility to remineralization are understood. Here, we present patterns in mangrove soil C stocks across hemispheres, latitudes, countries and mangrove community compositions, and estimate potential annual CO₂ emissions for countries where mangroves occur. Global potential CO₂ emissions from soils as a result of mangrove loss were estimated to be ∼7.0 Tg CO₂ e yr^-1. Countries with the highest potential CO2 emissions from soils are Indonesia (3,410 Gg CO₂ e yr^-1) and Malaysia (1,288 Gg CO₂ e yr^-1). The patterns described serve as a baseline by which countries can assess their mangrove soil C stocks and potential emissions from mangrove deforestation.