Geopolymer concrete (GC) is a synthetic material that combines sustainability and appropriate engineering properties, and it is relatively cost-effective compared to Portland cement-based concrete, its traditional competitor. Most GC studies have analyzed the microstructure and the chemical composition of GC. However, studies on the structural behavior of GC are limited. Thus this research focuses on the shear behavior of fly ash-based GC beams. Four GC beams and one conventional concrete beam were experimentally investigated to determine their shear strengths. The test variables included the shear span-to-effective depth ratio and the transverse reinforcement ratio of the investigated beams. The strength, strains, deformations, and mode of failure of the investigated beams are presented. The shear strengths of the investigated beams are comparable to those of conventional concrete beams.