A thermoplastic acrylic resin is provided. The thermoplastic acrylic resin is a graft copolymer in which a stem polymer is an acrylic resin containing acrylonitrile and another ethylenically unsaturated monomer, and a branch polymer is a polymer composed of an ethylenically unsaturated monomer. The acrylonitrile is contained in an amount of 35 mass % or more and 84.5 mass % or less, the other ethylenically unsaturated monomer is contained in an amount of 15 mass % or more and 64.5 mass % or less, and the polymer composed of an ethylenically unsaturated monomer is contained in an amount of 0.5 mass % or more and 40 mass % or less. Thus, provided are a thermoplastic acrylic resin having improved melt-processability without compromising heat resistance, a method for producing the thermoplastic acrylic resin, a thermoplastic acrylic resin composition, a molded body, an acrylic fiber, and a method for producing the acrylic fiber.