An electric motor and a compressor having an electric motor are disclosed herein. The electric motor may include a stator having a stator core and a stator coil, and a rotor provided with a rotational shaft and rotatably disposed with respect to the stator. The stator coil may include a main winding and an auxiliary winding connected to each other with a phase difference. The main winding may be divided into a plurality of main windings so as to be connected to each other and disconnected from each other, and the stator coil may further include a winding changeover switch configured to provide connection and disconnection between the plurality of main windings. Such a configuration may allow operating efficiency at a low load to be increased.