Nanoscale bacterial cellulose (BC) may be functionalized to provide advanced eco-friendly substrates. In the current work, BC was functionalized by magnetron sputtering of copper (Cu) to endow it with unique electromagnetic shielding properties while concomitantly improving mechanical, thermal, and conduction properties. The surface morphologies and chemical characteristics of BC/Cu nanocomposites were studied by atomic force microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and energy dispersive X-ray analysis system to conclusively demonstrate that Cu nanoparticles were evenly deposited on the surfaces. This topological construct enhanced the thermal stability, surface conductivity, mechanical properties, and interference (EMI) shielding effectiveness. EMI effects were also investigated by the four-point probe, uniaxial testing machine and a vector network analyzer that showed the BC/Cu nanoscale materials have high conductivity (0.026 S m−1), good mechanical properties (41.4 Mpa) and excellent EMI shielding (55 dB).