Ceramics have wide range of structural, aerospace and energy applications due to their thermal stability, corrosion resistance and superior mechanical properties. B4C is one of the high perfromance ceramics having superior hardness (˃35 GPa) along with low density (2.52 g.cm-3), high melting point (2763 °C), good wear resistance, corrosion resistance, ballistic efficiency and neutron absorption capacity. Due to its superior properties, it is widely used in wear resistant, neutron absorption and body armor applications in nuclear and defense sectors. However, poor sinterability and low fracture toughness (≈ 3 MPa m1/2) are the major limitations of B4C applications. Due to the strong B-C covalent bonding, it is extremely difficult to sinter it below 2000 °C using conventional sintering techniques. Spark Plasma Sintering (SPS) is one of the most promising techniques to sinter the high temperature ceramics at relatively lower temperatures with the advantages of shorter sintering time and limited grain growth. In order to achieve full densification of B4C, researchers have used various sintering additives such as Al, Si, Fe, Al2O3, TiC, Fe3Al, Ti3SiC2, Cr3C2, Fe50Mn30Cr10Co10, CaF2/Y2O3 and TiB2. TiB2 is one of the promising sintering additives in B4C due to its higher melting point (˃3000 °C), high electrical conductivity (0.07-0.12 M Ω-1 cm-1) and high hardness (around 35 GPa). Hence the addition of TiB2 is expected to enhance the machinability (using EDM), thermal stability, fracture toughness, flexural strength and hardness of the resultant B4C composites. In this study, low temperature sintering of B4C was attempted using reactive Ti-B mixture as a sintering aid. Wet ball milling was used to produce mechanically activated powder mixture of elemental Ti-B and to homogeneously disperse them with B4C powders. The in-situ formed TiB2 is expected to act as a sintering additive and enhance densification at lower sintering temperature and to increase hardness and fracture toughness of the resultant B4C composites. Dense B4C composite compacts were obtained using spark plasma sintering (SPS) at 1400°C. Ti and B powders (1:2 atom ratio) were milled for 8 h and added to B4C powder in proportions of 5, 10, 20 wt.% and milled for another 4 h to achieve good dispersion. Significant WC contamination was observed due to the wear of the balls and vials. Dense and pore free microstructure consisting of B4C grains surrounded by the fine grains of (W,Ti)B2 and W2B5 was observed. The activation energy for sintering reduced from 657 to 197 kJ/mol with the addition of 20 wt.% Ti-B mixture. The B4C-5TiB2 sample showed the maximum hardness of 3225 ± 218 HV.