This study aims to enhance the compressive behavior of concrete-filled steel tubular (CFT) columns using external spiral confinement and to examine whether steel tube thickness can be reduced without a significant loss in ultimate load-carrying capacity. Column behavior was investigated through an experimental program combined with optimization, using axial compression tests and extracting force–displacement curves. Two groups of specimens were fabricated and tested: concrete-filled steel tubular (CFT) and externally spirally confined (OSCFT) columns with a 45 mm pitch. The experimental results showed that external spiral confinement improves the compressive response of OSCFT columns compared with CFT specimens. The average absorbed energy for the OSCFT and CFT specimens was 8044 J and 7169 J, respectively, indicating an increase of about 12% in energy absorption due to external confinement. To evaluate the potential to reduce steel consumption while maintaining equivalent axial capacity, the corresponding tube thicknesses of CFT columns were determined using a Differential Evolution (DE) algorithm to match their axial capacity to that of the OSCFT specimens. The optimized equivalent thickness of the CFT columns ranged from 3.29 to 3.91 mm, with an average of 3.51 mm, showing an average reduction of approximately 8.55% in thickness and steel consumption. Furthermore, the convergence of the DE algorithm within fewer than 25 generations confirmed that the optimization process achieved stable, reliable solutions within the experimental range of this study.