This study investigates the mechanical and durability performance of Fibre-Reinforced Geopolymer Concrete (FRGPC) incorporating varying proportions of polypropylene fibres. M40-grade geopolymer concrete was prepared using Class F fly ash as the primary binder, and fibre content was varied from 0% to 1%. Key experimental evaluations included slump cone test, compressive strength, splitting tensile strength, flexural strength, ultrasonic pulse velocity (UPV), water absorption, and cost analysis. The results showed that up to 0.6% fibre content (FRGP-3) significantly enhanced all mechanical strengths, with compressive strength increasing by up to 35%, tensile strength by 52%, and flexural strength by 19% over the control mix. The UPV and water absorption tests confirmed improved density and reduced porosity, indicating superior durability. Beyond 0.6% fibre content, workability and strength declined due to fibre agglomeration and increased voids. The study concludes that FRGP-3 offers an optimal balance of strength, durability, and cost-effectiveness, making it a sustainable alternative to conventional concrete for structural applications. Keywords: Geopolymer Concrete, Fly Ash, Compressive Strength, Flexural Strength, UPV, Water Absorption