Process parameter optimisation is often performed to improve process efficiency and cost-effectiveness. To fabricate stainless steel (SS316)-10 wt% boron carbide (B4C) composite, spark plasma sintering is being researched for the process parameter optimisation of temperature, pressure, dwell time, and heating rate. The sintering operation was carried out utilising the grey relational analysis and an analysis of variance to determine the impacts of the response variables micro-hardness and density. The spark plasma sintering technique is used to solidify the composite powders under a wide range of conditions, including temperatures of 800 °C, 900 °C, and 1000 °C; pressures of 60 MPa, 70 MPa, and 80 MPa; dwell times of 5 min, 10 min, and 15 min; and heating rates of 100 °C/min, 200 °C/min, and 300 °C/min. Scanning electron microscopy, Micro Vickers hardness testing, and Archimedes-based density testing are being used to examine the microstructure, hardness, and density of sintered compacts. The findings revealed that the sintering temperature and pressure had a significant influence on the compacts’ properties. The ideal circumstances for spark plasma sintering parameters in this research include 900 °C temperature, 70 MPa pressure, 10 min of dwell time, and a heat rate of 200 °C/min, resulting in a high density of 7.35 g/cm3 and an optimum level of microhardness of 1450 HV.