The construction industry faces growing demands for sustainable and resilient materials, prompting an increase in research on alternative binders to reduce environmental impact. One promising approach involves the use of steel fibers and ground granulated blast furnace slag (GGBS) in geopolymer concrete (GPC), which offers the benefits of reduced cement reliance and enhanced mechanical properties. This study explores the mechanical behavior of GGBS-based geopolymer concrete reinforced with varying steel fiber volumes, using compressive strength, flexural strength, and split-cylinder tensile tests to assess performance. Results demonstrate that the addition of steel fibers substantially improves tensile and flexural strength, enhancing the material’s durability and flexibility compared to traditional cement-based concrete. With its lower environmental impact and superior mechanical properties, steel fiber-reinforced GGBS geopolymer concrete aligns with the sustainable goals of Industry 5.0. This research provides valuable insights into optimizing GPC for advanced manufacturing and infrastructure applications, contributing to a digital and sustainable future in construction.