The high cost and limited availability of steel reinforcement within trade fairs, particularly for required diameters and quantities, have become significant challenges. Normal concrete has a density of 2400 kg/m³, it results in high dead weights for structural elements and exhibits low tensile strength. The primary straining action faced by reinforced concrete solid slabs is the bending moment. To enhance the flexural strength of these structural solid slab elements, one effective approach is to reduce the dead weight using lightweight concrete, which has a density range of 300 to 1900 kg/m³. This method also increases the tensile strength of the concrete. Incorporating polypropylene fiber (PPF) into the admixture enhances energy absorption capacity and controls crack propagation. Furthermore, substituting reinforcing steel bars with Glass Fiber Reinforced Polymer (GFRP) bars, which possess high ultimate strength and are non-corrosive, provides significant benefits. This paper aims to experimentally, numerically, and analytically study the impact of PPF on the behavior of lightweight foamed concrete slabs (LWFC) reinforced by GFRP bars. This comprehensive research also explores the mechanisms to improve the mechanical properties of concrete. Key parameters affecting structural behavior addressed in the study include fiber volumetric ratio, fiber aspect ratio, type of reinforcement (steel vs. GFRP). The paper utilizes the ABAQUS nonlinear structural program for a numerical finite element analysis to predict the ultimate load. Additionally, an analytical study was conducted to calculate the solid slabs' ultimate loads using code provisions for modeling the equivalent stress block for fibrous concrete in both tension and compression.