The rapid progress in telecommunications over the past decade brought about a societal revolution. However, the proliferation of electromagnetic waves has also presented significant challenges that require our attention. In this regard, we presented a simple spray-coating method for developing a lightweight and flexible graphene-coated MXene film for terahertz shielding. The MXene/graphene layered structure, with a 3:1 wt ratio and a thickness of 1.63 μm, achieved a shielding effectiveness (SE) of 47 dB, which was remarkably similar to that of the pristine MXene with a thickness of 0.8 μm. Notably, even after one month of storage, the SE of the composite consisting of 75 wt % MXene-25 wt % Graphene remained at 94% of its initial value. In contrast, the SE was reduced to 72% of its initial value in the case of 100 wt % MXene. The hydrophobic graphene layer, acting as a barrier against water molecules, emerged as the key factor responsible for maintaining the shielding efficiency. Furthermore, theoretical modeling based on the transfer matrix method was employed to correlate the behavior of electromagnetic waves at different interfaces of thin films.