Provided is a thermoplastic resin composition which includes: a first copolymer including an acrylic graft copolymer; a second copolymer including an alkyl-substituted styrene-based monomer unit, a vinyl cyanide-based monomer unit, and a (meth)acrylate-based monomer unit; and a third copolymer including an alkyl-unsubstituted styrene-based monomer unit, a vinyl cyanide-based monomer unit, and a (meth)acrylate-based monomer unit. According to the present invention, a thermoplastic resin composition and a thermoplastic resin molded article, which are excellent in heat resistance, colorability, and scratch resistance, can be provided.