Harmonic mitigation in grid-connected photovoltaic (PV) systems is crucial for maintaining power quality and ensuring efficient energy transfer to the grid. Employing a shunt active filter (SAF) in MATLAB offers an effective solution to mitigate harmonic distortions. By analyzing the system's current and voltage waveforms, the SAF dynamically compensates for harmonics, effectively reducing their impact on the grid. Through real-time control algorithms implemented in MATLAB, the SAF actively detects and cancels out unwanted harmonics, thereby enhancing the overall stability and reliability of the PV system. This approach not only ensures compliance with grid standards but also optimizes power transfer efficiency, making it a viable and practical solution for grid-connected PV installations.