Harmonic mitigation is the academic field and engineering practice focused on the identification, analysis, and reduction of harmonic distortions within electrical power systems. This research area investigates the generation of harmonic currents and voltages by nonlinear loads, their propagation and effects on system impedance and voltage waveforms, and develops methodologies—such as passive filtering, active power filtering, and advanced control strategies—to counteract harmonic pollution, thereby enhancing power quality, improving system reliability, and preventing equipment damage.