Ni and Ni-matrix-nanocomposite thin films were produced by constant-current electrodeposition from a sulphamate bath. The composite consisted of an array of Ag-coated SnO2 nanowires grown onto a substrate, around which the Ni matrix was deposited. The hardness and Young's modulus of the films were studied by microindentation, showing a strengthening of 66% for the composite with respect to Ni films produced using the exact same bath and deposition parameters as the composite's matrix. A straightforward method for evaluating the stress–strain relationship from indentation data based on analytical and computational models available in the literature was proposed and evaluated. A thorough microstructure characterisation by scanning electron microscopy together with electron backscatter diffraction was conducted to assist in the interpretation of the mechanical response of the films. The Ag–SnO2 in the composite prevented the development of texture and was responsible for a grain size reduction of 85%.