A series of experiments were conducted to study the structural behavior of conventionally reinforced (GR-GPC), steel fiber-reinforced (SFR-GPC), and post-tensioned (PS-GPC) geopolymer concrete beams with geometrical similarities. The geopolymer concrete mixtures were prepared by using fly ash (FA) as a precursor. A mixture of sodium hydroxide and sodium silicate solution was used as an alkaline activator to prepare geopolymer specimens. All concrete specimens were cured at 65 °C in a specially fabricated hot air curing chamber that is an alternative to the conventional oven. The final mix for the beams was selected based on the substantial trial mix studies conducted by varying FA content and steel fiber volume fractions. The experimental investigations are confined to studying the flexural behavior under the two-point load testing. The investigated structural parameters are cracking load, ultimate load, deflections, stiffness, ductility ratio, and failure patterns of these beams. Few important conclusions were drawn based on the discussion and comparison of results. The performance of SFR-GPC and PS-GPC was found to be superior compared to conventionally reinforced GPC beams in all structural parameters investigated.