An electric motor and a compressor having an electric motor. The electric motor may include a stator, and a rotor provided with a rotational shaft, a rotor core coupled to the rotational shaft, and permanent magnets coupled to the rotor core. The rotor core may include a first core to which the permanent magnets may be coupled, and a second core made of a magnetic material and coupled to an end of the first core in an axial direction. The second core may have outer surfaces disposed inside of extension lines extending in the axial direction from inner surfaces of the permanent magnets.