GFRP rebars can effectively address the corrosion issue of steel rebars, which are used in concrete structures. However, their application in tunnel lining segment is less prevalent. A sandwich segment is composed of an interior functional layer and two exterior concrete layers, which are connected by connectors. This paper investigates the flexural behavior of GFRP-reinforced concrete solid and sandwich segments and compare them with those of steel-reinforced concrete segments, based on a combined experimental and finite element (FE) study. To this end, four-point bending tests were first conducted on GFRP-reinforced concrete solid and sandwich segments. The experimental results indicated that the ultimate loads of the two full-scale solid and sandwich tunnel segments were 624 kN and 384 kN, respectively. The difference was attributed to the different configurations of the segments and the existence of the connectors for the sandwich segment. Next, FE models were constructed. There is a good correlation between the experimental and FE results for both segments, proving the accuracy of the FE models. Further, the FE model was used to model a steel-reinforced concrete solid segment. Based on the FE results, the ultimate load and displacement of GFRP-reinforced solid segments are 6.9% and 64% higher than those of steel-reinforced solid segments. It can be concluded that both GFRP-reinforced concrete solid and sandwich segments demonstrate enough loading capacity to be used as lining segments. In comparison to steel-reinforced segments, GFRP reinforcement improves both the ultimate bearing and deformation capacity of the concrete segments, thereby proving the feasibility of replacing steel rebars with GFRP rebars in lining segments.