Durability of rectangular reinforced concrete poles used in electric power distribution networks has become a significant environmental, structural, and economic challenge, primarily due to the corrosion of steel reinforcement. Considering the extensive utilization and vital role of these poles in national infrastructure, this study investigates the feasibility of using glass fiber–reinforced polymer (GFRP) reinforcing bars as an alternative reinforcement to promote the service life of these poles. For this purpose, two poles reinforced with conventional steel reinforcements and five poles reinforced with GFRP reinforcing bars were fabricated and tested under flexural loading as per relevant guidelines. In addition to load-carrying capacity, crack propagation, deflection, failure mode, concrete and reinforcement strain, ductility, and stiffness of both types of poles were evaluated and compared together. The results indicated that the strength performance of GFRP-reinforced poles could successfully satisfy the required design criteria stipulated in relevant design guildeline for steel reinforced poles. However, serviceability criteria—namely cracking and deflection—necessitate enhancement in these poles. By increasing the reinforcement ratio, GFRP-reinforced poles were able to meet most of the existing code requirements established for steel-reinforced poles. Results of the current study can pave the road towards utilization of GFRP composite bars in reinforcing electric power concrete poles and developing related design guidelines.