A polypropylene resin composition includes a base resin, a thermoplastic elastomer, and an inorganic filler. The base resin is a polypropylene-based mixed resin including a first resin, a second resin, a third resin, and a fourth resin. The first resin is a homopolypropylene resin. The second resin, the third resin, and the fourth resin are each a polypropylene-based block copolymer resin. A melt index of the second resin measured at a temperature of 230° C. and under a load of 2.16 kg is higher than a melt index of each of the third resin and the fourth resin measured under the same condition. A flexural modulus of the third resin measured in accordance with ASTM D790 is lower than a flexural modulus of the fourth resin measured under the same condition.