<p>This study examines the flexural performance of cellular stainless-steel beams (cssbs) with circular web openings associated with experimental validation, statistical analysis, and sustainability evaluation. Cssbs are advantageous in reducing weight and material use, while the weight reduction negatively affects flexural strength and introduces new failure mechanisms such as shear buckling and local yielding. Three-point bending tests were conducted on welded austenitic stainless-steel beams (en 1.4301), comparing cssbs to solid stainless-steel beams (ssbs). Experimental results revealed a 16.77% reduction in flexural capacity and a 12% decrease in stiffness for cssbs relative to ssbs, accompanied by increased mid-span deflections under identical loading. Statistical analysis found a strong relationship (r²=0.96) between web opening geometry and reduction in capacity, while significance testing showed the influence of all perforation parameters. Modes of failure were found to differ between cssbs and ssbs. An analytical model is proposed that predicts loss of strength as a function of web opening, while being supported by eurocode (en 1993-1-4), and aims to manage limitations of existing design codes for perforated stainless-steel beams. In addition, the study addresses sustainability of cssbs with an observation of over 90% recyclability of material, and reduced weight, approximately 12% overall. While cssbs had an increased initial cost per kg of material, they will offer economic and environmental benefits over the life of the structure and any recycled material. The study cumulatively provides evidence to support the use of cssbs in sustainable structural designs, and it demonstrates experimental values and models intended for practice.</p>