Broad applications of fiber-reinforced polymer reinforcement are hindered by its elastic brittle behavior, resulting in reduced structural ductility. In addition, due to the lower modulus of elasticity, serviceability considerations such as deflection and crack width control present serious challenges to designers. This paper reports new means to address these issues by introducing engineered cementitious composite (ECC), which is designed based on micromechanics principles and exhibits higher tensile and shear ductility, to replace brittle concrete matrix. Three series, totaling 16 GFRP reinforced beams with various shear span-depth and longitudinal reinforcement ratios, were tested. Results reveal that, under the same reinforcement configurations, ECC beams exhibit significant increases in flexural performance in terms of ductility, load-carrying capacity, shear resistance, and damage tolerance compared with the counterpart high-strength concrete (HSC) beam. The extent of improvement strongly depended on the failure mode. Moreover, ECC beams without shear reinforcement show better performance than HSC beams with dense steel stirrups, suggesting elimination of shear reinforcement is feasible when the concrete matrix is replaced by ECC.