Ti₃C₂T_x-MXene-based nanocomposites were prepared with 1D Mn₂O₃ through the electrostatic self-assembly method. The synthesized nanocomposites are investigated for photocatalytic degradation of individual dye, mixed cationic and anionic dyes under visible light irradiation. The cubic bixbyite structure of 1D Mn₂O₃ was confirmed in the nanocomposites by the XRD and Raman spectroscopy analyses. The band gap energy of the 1D Mn₂O₃-Ti₃C₂T_x MXene (5–20 wt%) nanocomposites was estimated to range from 0.9 eV to 0.2 eV through the Tauc plot, implying their application as a photocatalyst under visible light illumination. The randomly oriented nanorods were decorated on the accordion-like Ti₃C₂T_x MXene sheets and were confirmed by the SEM, FESEM and TEM analyses. The average diameter of Mn₂O₃ nanorods (87 nm) and interlayer spacing of Ti₃C₂T_x MXene sheets (172 nm) were measured from FESEM analysis. The Mn, O, Ti, C and F elemental compositions of the composites were analyzed by the EDAX. The 100% degradation efficiency of methylene blue (MB) dye was achieved in the presence of 1D Mn₂O₃-Ti₃C₂T_x (20 wt%) nanocomposite and the same was used to degrade the mixed cationic and anionic dyes. In mixed dyes, methyl orange (MO), rhodamine B (RhB) and methylene blue (MB) achieved degradation efficiencies of 82%, 80% and 96%, respectively. Based on the scavenger's experiment, the hydroxyl radical ($\mathrm{O}{\mathrm{H}}^{-})$ and superoxide anion radicals ${(\mathrm{O}}_2^{°-})$, were the dominant reactive species in the dye degradation.