This study focuses on evaluating the crashworthiness performance of glass fiber-reinforced epoxy (GFRE) multi-cell circular structures subjected to quasi-static lateral loading. To this end, GFRE single-cell and multi-cell (two cells and four cells) tubes were manufactured while carefully ensuring that all specimens possessed identical overall dimensions and closely matched mass by adjusting the fiber and matrix content accordingly. In addition, the influence of foam filling on the crashworthiness behavior of both single-cell and multi-cell GFRE tubes was systematically investigated. During testing, load–displacement responses were recorded, and the failure modes of the structures were carefully documented. Key crashworthiness metrics like initial peak force ( ), total energy absorbed (U), mean crash force ( ), specific energy absorption (SEA), and crash force efficiency (CFE) were calculated to comprehensively assess how well the tubes dissipate energy. Experimental findings revealed that both the number of cells and the presence of foam filling have a significant impact on the crashworthiness performance of GFRE tubes. Among all tested configurations, the two-cell foam-filled (C2F) tubes exhibited the most favorable overall crashworthiness metrics, achieving an of 0.9 kN, U of 115.20 J, of 1.13 kN, and SEA of 2.38 J/g. Furthermore, the foam-filled single-cell configuration (C1F) achieved the highest CFE of 2.71.