Provided is a thermoplastic resin composition a resin molded article of which has excellent mechanical strength. The thermoplastic resin composition comprising: a thermoplastic resin; relative to 100 parts by weight of the thermoplastic resin, 0.01 to 30 parts by weight of an additive having a Mohs hardness of 5.5 or larger; and 10 to 200 parts by weight of glass fiber, wherein the glass fiber comprises SiO2 and Al2O3 in a proportion of 60 to 70% by weight of SiO2 and 20 to 30% by weight of Al2O3.