A permanent magnet motor is a type of electric motor that uses permanent magnets for the field excitation and a wound armature. The permanent magnets can either be stationary or rotating; interior or exterior to the armature for a radial flux machine or layered with the armature for an axial flux topology. The schematic shows a permanent magnet motor with stationary magnets outside of a brushed armature (a type commonly used on toy slot-cars).

This type of motor is used in GM's Chevrolet Bolt and Volt, and the rear wheel drive of Tesla's Model 3. Recent dual motor Tesla models use a combination of a permanent magnet motor at the back and traditional induction motor at the front.

Permanent magnet motors are more efficient than induction motor or motors with field windings for certain high-efficiency applications such as electric vehicles. Tesla's chief motor designer was quoted discussing these advantages, saying:

It's well known that permanent magnet machines have the benefit of pre-excitation from the magnets, and therefore you have some efficiency benefit for that. Induction machines have perfect flux regulation and therefore you can optimize your efficiency. Both make sense for variable-speed drive single-gear transmission as the drive units of the cars. So, as you know, our Model 3 has a permanent magnet machine now. This is because for the specification of the performance and efficiency, the permanent magnet machine better solved our cost minimization function, and it was optimal for the range and performance target. Quantitatively, the difference is what drives the future of the machine, and it's a trade-off between motor cost, range and battery cost that is determining which technology will be used in the future.

Permanent magnet motors consist of two main types. Surface permanent magnet motors (SPM) and internal permanent magnet (IPM) motors. The main difference is that SPM motors place the magnets on the outside of the rotor while IPM motors place their magnets inside the motor. Benefits to internal magnets include structural integrity and reducing Back EMF. Since holes must be cut into the rotor for the placement of the magnets this creates areas of high reluctance allowing carmakers to obtain some of the benefits of reluctance motors as well as of permanent magnet motors.

Back electromotive force (EMF) is also known as the counter-electromotive force. It is the voltage that occurs in electric motors from the relative motion between the stator windings and the rotor’s magnetic field. The rotor's geometry determines the waveform's shape.

This effect is not unique to permanent magnet motors. Induction motors also suffer from it. However in an induction motor the fields from the rotor decrease as speed increases. A permanent magnet motor generates its own constant field. This means that as speed increases a voltage is induced linearly with the speed on the stator. This voltage is negative to the voltage provided to the motor and thus is a loss to the overall system.

Many different permanent magnetic materials are used to drive permanent magnetic motors and vary based on multiple factors, principally necessary magnetic strength and cost. The four primary permanent magnetic materials that are found in the vast majority of industrial applications are neodymium iron boron (NdFeB), samarium cobalt (SmCo), aluminum nickel cobalt (Alnico), and strontium carbonate-iron oxide (also known as “ceramic magnet”); furthermore, significant materials science research is ongoing into the development of additional non-rare earth (NRE) permanent magnetic materials.