High strength SiC whisker-reinforced Ti₃SiC₂ composites (SiC_w/Ti₃SiC₂) with an improved thermal conductivity and mechanical properties were fabricated by spark plasma sintering. The bending strength of 10 wt% SiC_w/Ti₃SiC₂ was 635 MPa, which was approximately 50% higher than that of the monolithic Ti₃SiC₂ (428 MPa). The Vickers hardness and thermal conductivity (k) also increased by 36% and 25%, respectively, from the monolithic Ti₃SiC₂ by the incorporation of 10 wt% SiC_w. This remarkable improvement both in mechanical and thermal properties was attributed to the fine-grained uniform composite microstructure along with the effects of incorporated SiC_w. The SiC_w/Ti₃SiC₂ can be a feasible candidate for the in-core structural application in nuclear reactors due to the excellent mechanical and thermal properties.