<p>Steel–concrete composite beams are indispensable in modern construction for their high structural efficiency, effectively utilizing the tensile strength of steel and the compressive strength of concrete. Over time, these beams are susceptible to deterioration caused by environmental factors, increased load demands, loading patterns and aging of materials. Fiber-Reinforced Polymer (FRP) composites have emerged as a transformative solution for the strengthening of such structural members. Current study explores the application of FRP materials in strengthening steel–concrete composite beams, highlighting different strengthening techniques such as externally bonded (EB) reinforcements and near-surface mounted (NSM) systems. The findings show that FRP strengthening techniques substantially improve beam performance, with load capacity increase between 26 and 116% and stiffness enhancements from 25 to 126%. The study also discusses failure modes, including FRP debonding, concrete crushing, and steel yielding. It further emphasizes the advantages of using various FRP types in maintaining composite action and enhancing load carrying capacity and parameters that influence structural performance. The performance of strengthened beams depends on FRP thickness, layout, degree of shear connection, and level of prestress. Additionally, the study identifies existing gaps in the current literature in connection to the performance of FRP-strengthened composite beams and outlines the potential future research directions aiming to enhance the understanding of flexural behaviour and failure mechanisms.</p>