A cooling device for an internal combustion engine including: an ebullient cooling system in which a refrigerant cools the internal combustion engine by boiling in the internal combustion engine, and a rankine cycle system including a superheater that superheats the refrigerant discharged from the internal combustion engine, a turbine to which the refrigerant discharged from the superheat is supplied, and a condenser that condenses the refrigerant discharged from the turbine; wherein the rankine cycle system includes a supply path that supplies a liquid-phase refrigerant discharged from the condenser to a shaft part of the turbine, and a first supply part of the condenser to which the refrigerant discharged from the turbine is supplied is arranged higher than the shaft part of the turbine in a gravity direction.