The electrical conductivity of shock‐compressed liquid oxygen has been measured in the dynamic pressure range 18–43 GPa(180–430 Kbar). A double‐shock equation‐of‐state point was also measured. The data and Hugoniot calculation, based on a chemical equilibrium model, indicate that liquid oxygen partially dissociates and forms a two‐component conductive fluid. Details of the experimental design are given and the data are discussed in terms of electronic transport in disordered systems.