The present application provides an automobile seat cushion comprising: a body shaped like a flat sheet that has a top surface in contact with the buttocks of a user and a bottom surface in contact with an automobile seat; a plurality of protrusions that are distributed under the bottom surface of the body and provided to vertically protrude downward from the bottom surface, the plurality of protrusions being formed integrally with the body of the seat cushion; and a plurality of vertical ventilation holes that are formed to be recessed downward from the top surface of the body, the plurality of vertical ventilation holes and the plurality of protrusions being in one-to-one correspondence vertically, wherein each vertical ventilation hole of the plurality of vertical ventilation holes vertically extends downward beyond the bottom surface of the body from the top surface of the body, and enters into a corresponding protrusion but does not penetrate through a bottom of the corresponding protrusion, and wherein each protrusion of the plurality of protrusions is provided with a horizontal ventilation hole that penetrates through at least one side surface of the protrusion, and the horizontal ventilation hole and the vertical ventilation hole meet and communicate with each other in the protrusion.