Reinforced concrete (RC) beams experience significant strength degradation when exposed to fire, especially those reinforced with fiber-reinforced polymer (FRP) bars, which are highly vulnerable to thermal damage. This study experimentally investigates the flexural performance of full-scale fire-damaged concrete beams reinforced with glass FRP (GFRP) bars and retrofitted using carbon fiber-reinforced cementitious matrix (C-FRCM) U-wraps. A beam was exposed to fire in accordance with ASTM E119 for a duration of three hours. Following fire exposure, the beam was strengthened with a single layer of C-FRCM U-wrap and tested under four-point bending. A second beam, which was neither exposed to fire nor strengthened with C-FRCM, served as the control specimen. Both test specimens had uniform dimensions of 300 mm in width, 400 mm in depth, and 5000 mm in length. The test results showed that the strengthened fire-exposed beam gained only 40% of its flexural capacity compared to the control beam. These findings demonstrate that the effectiveness of C-FRCM retrofitting in fire-damaged GFRP-reinforced concrete beams strongly depends on the level of thermal degradation sustained by the internal reinforcement. While the C-FRCM system can partially restore flexural capacity, adequate fire protection is essential to achieve full performance recovery.