By means of slow solvent evaporation method, single crystals of Strontium chloride-doped Tetrakis Thiourea Barium Chloride (STTBC) were grown. Single crystal X-ray diffraction study has been utilized to get the values of cell parameters and to establish the monoclinic nature of the STTBC crystal. The powder XRD diffractogram defined the crystalline nature of the STTBC sample. The UV-Vis spectral study on STTBC has been employed to figure out its transmittance and cut-off wavelength. The values of significant optical constants such as reflectance, band gap energy and refractive index have also been calculated using UV-Vis spectral study. Vickers micro hardness analysis has been carried out to ascertain the mechanical strength of the synthesized crystal. The mechanical studies have inferred that the STTBC crystal exhibited reverse indentation size effect. The SHG efficiency of the STTBC sample has been observed to be 1.06 times higher than that of the parent crystal TTBC.