Dispersion of 2D carbon nitride (C 3 N 4 ) nanosheets into a nickel phosphorous (NiP) matrix was successfully achieved by ultrasonication during the electroless plating of NiP from an acidic bath. The morphology and thickness, elemental analysis, phases, roughness, and wettability for as-plated and heat-treated nanocomposite were determined by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, atomic force microscopy, and contact angle measurements, respectively. C 3 N 4 showed a homogeneous distribution morphology in the nanocomposite that changed from amorphous in case of the NiP to a mixed crystalline-amorphous structure in the NiP-C 3 N 4 nanocomposite. The microhardness and corrosion resistance of the as-plated nanocomposite and the heat-treated nanocomposite coating were significantly enhanced compared to the Ni-P. The nanocomposite showed a superior corrosion protection efficiency of~95%, as observed from the electrochemical impedance spectroscopy (EIS) measurements. On the other hand, the microhardness of the nanocomposite was significantly increased from 780 to reach 1175 HV 200 for NiP and NiP-C 3 N 4 , respectively.