This research investigates the flexural performance of strengthened rubberized concrete beams via bottom, side, and hybrid near-surface mounted (NSM) approaches using GFRP/steel rebars. Eleven strengthened specimens, alongside one control, were subjected to four-point loading setup till failure. The investigation focused on three key parameters: strengthening technique (bottom, side, or hybrid), NSM bar area, and bar type (GFRP or steel). The results revealed significant improvements across various performance metrics. It was demonstrated that NSM strengthening enhanced the beam’s cracking loads by up to 90%. Correspondingly, the strengthened beam’s yield and ultimate loads witnessed enhancements up to 48% and 79%, respectively. Notably, the load-carrying ability of GFRP bars consistently outperformed steel bars. Additionally, increasing the quantity of NSM strengthening proved beneficial, with bottom placement offering a slight advantage due to a larger internal lever arm. The proposed hybrid NSM technique, employing three 8-mm-diameter GFRP bars, emerged as the most effective strengthening scheme. However, utilizing four bars resulted in decreased effectiveness due to overlapping tensile stresses and accelerated debonding failure. Finally, the experimental results were compared to analytical predictions, with close agreement observed. The experimental-to-predicted analytical result ratio varies from 0.84 to 1.01%, indicating the validity of the analytical approach.