Provided is a nonvolatile memory device and a method of forming the nonvolatile memory device. The nonvolatile memory device includes a floating gate formed on a first active region doped with a first-conductivity-type dopant. The floating gate is doped with the first-conductivity-type dopant. Therefore, the thickness of a tunnel insulation layer can be kept thin, and the threshold voltage of a nonvolatile memory cell including the floating gate can be increased. As a result, the endurance of the tunnel insulation layer and the data retention characteristics of the nonvolatile memory cell is improved.