External bonding of Glass fiber reinforced polymer (GFRP) sheets to the periphery of steel circular hollow sections (CHS) is a new technique for structurally improving such sections. This paper involves in analyzing the capacity of GFRP-strengthened steel CHS tubes subjected to bending. The main aim of wrapping GFRP sheets is to reduce the buckling behavior of CHS. Design of GFRP sheets for strengthening tubular steel sections necessitates the prediction of the capacity of confined steel circular sections. This paper presents a design method for evaluating the capacity of GFRP-strengthened steel CHS subjected to bending. The hoop FRP reduces the effect of local buckling by restraining the tube wall. The influence of hoop CFRP is considered in the proposed method by taking its modulus of elasticity as a proportion of the elastic modulus of longitudinal GFRP. The excitation of the longitudinal GFRP minimizes the effect of local buckling in the tube wall, which ultimately increases the local flexural stiffness and strength of the tube.