Glass Fiber Reinforced Polymer (GFRP) has emerged as a popular choice for structural elements in civil engineering due to its lightweight, high strength, and corrosion resistance. However, GFRP is vulnerable to damage such as matrix cracks and delamination when subjected to high-impact or high-cyclic loads, despite its durability. Presently, visual inspection is the main method available for detecting such damage, highlighting the need for an effective monitoring approach. This study proposes a new damage monitoring method for GFRP. Specifically, the approach involves the attachment of two aluminum plates on both sides of the GFRP to form a parallel plate capacitor. The capacitance of the capacitor is anticipated to decrease in response to damage in the GFRP. The proposed method was tested under static and cyclic loading conditions to evaluate its efficacy. The specimen was subjected to tensile stress, resulting in internal damage such as matrix cracks and delamination. The results of the static test indicated that the capacitance decreased with increasing load. Similarly, in the cyclic loading test, the capacitance decreased with increasing loading cycles. However, it was observed that the aluminum plates on the GFRP partially debonded, indicating that debonding of the aluminum plates and delamination of the GFRP have a more significant impact on capacitance than matrix cracks in GFRP.