This work investigates the effect of cellular configuration and polyurethane (PU) foam infill on the crashworthiness performance of square glass fiber–reinforced epoxy (GFRE) composite tubes. Single-cell and multicell (two-cell and four-cell) GFRE tubes were fabricated using a manual wet-wrapping lay-up process. All specimens were carefully designed to have identical external dimensions and closely matched mass by adjusting the fiber and matrix content to ensure consistency across configurations. The influence of PU foam infill on the energy absorption characteristics of both single-cell and multicell structures was systematically evaluated under quasi-static lateral compression. Key crashworthiness indicators, including initial peak force, total energy absorbed (U), mean crashing force, crash force efficiency (CFE), and specific energy absorption (SEA), were derived from load–displacement data and failure observations. A hybrid Analytic Hierarchy Process-Technique for Order Preference by Similarity to Ideal Solution (AHP-TOPSIS) multi-attribute decision-making framework was used to rank the structural configurations based on their crashworthiness. Experimental results demonstrated that the OCF (one-cell foam-filled square) structure exhibited superior performance in terms of , U, , and SEA, reaching values of 1.93 kN, 102.90 J, 1.43 kN, and 2.42 J/g, respectively. The TC (two-cell unfilled square) structure yielded the highest CFE at 1.11. The AHP-TOPSIS analysis further identified the FCF (four-cell foam-filled square) configuration as possessing the most desirable overall crashworthiness profile due to an optimal balance of all key indicators.