This study presents a performance-based comparative assessment of two widely used confinement-oriented post-fire strengthening techniques for reinforced concrete (RC) structures: externally bonded carbon fiber–reinforced polymer (CFRP) confinement and steel jacketing. A representative interior RC column extracted from a parking structure is evaluated under three explicitly defined fire-damage states (low, moderate, severe), in which thermal exposure is translated into residual material degradation for concrete and reinforcing steel. Both strengthening systems are then designed and analytically represented within a unified framework to enable consistent comparison across damage severities. Results indicate that fire exposure causes a disproportionate reduction in deformation capacity relative to strength, shifting failure behavior toward brittle, deformation-controlled mechanisms. Both CFRP and steel jacketing effectively restore post-fire capacity; however, their performance profiles diverge as damage severity increases. CFRP provides efficient strength recovery and moderates brittleness, but its deformation enhancement remains constrained by interface sensitivity in fire-damaged substrates. Steel jacketing delivers more stable confinement, greater ductility recovery, and higher energy absorption, with its relative advantage becoming most pronounced under moderate to severe fire damage. Overall, the study demonstrates that post-fire strengthening selection should prioritize deformation reliability and failure stability over strength recovery alone, particularly for gravity-dominated parking structures with limited redundancy.