Abstract: Textile-reinforced mortar (TRM) exhibits excellent durability and compatibility with concrete substrates for strengthening reinforced concrete (RC) structures. In this study, four-point bending tests were conducted on six RC two-way slabs to investigate the effects of concrete strength (C15 and C30) and strengthening schemes (mortar-only, single-layer TRM, and double-layer TRM) on the flexural performance of RC two-way slabs. The results show that TRM strengthening significantly increases the cracking load, flexural stiffness, and ultimate load capacity of the slabs. In particular, double-layer TRM strengthening is the most effective for low-strength concrete slabs, resulting in an increase of 68% in ultimate load capacity and an increase of 160% in post-cracking stiffness. Moreover, the TRM layer effectively restricts crack propagation, leading to a finer and more uniform crack distribution at the slab bottom. The failure modes of the strengthened specimens are mainly controlled by textile slippage or rupture, effectively preventing the brittle failure of the slabs.