Large-area heteroatom-doped graphene films are greatly attractive materials for various applications, such as electronics, fuel cells, and supercapacitors. Currently, these graphene films are prepared by the high-temperature chemical vapor deposition method, which produces a low doping level in N-doped graphene (NG) and fails in the synthesis of large-area S-doped graphene (SG) film. Here, we report a low-temperature method toward the synthesis of large-area heavily heteroatom-doped graphene on copper foils via a free radical reaction using polyhalogenated aromatic compounds. This low-temperature method allows the synthesis of single-layer NG film with a high nitrogen content, and the production of large-area SG film for the first time. Both doped graphenes show enhanced electrical properties in field effect transistors as well as high-performance electrocatalysts for fuel cells.