<p>Titanium silicon carbide (Ti₃SiC₂) is one of the significant phases in the MAX (M_<i>n</i>+1AX_<i>n</i>) system. Its high thermal conductivity, low hardness, and excellent resistance to thermal shock, corrosion, and oxidation make it a popular reinforcement material for novel ceramic composite designs. On the other hand, 12 mol% ceria-stabilized tetragonal zirconia polycrystals (12Ce-TZP) are known for their extremely high fracture toughness due to martensite-like phase transformations; however, they exhibit low thermal conductivity. Therefore, the scope of the current research is to investigate 12Ce-TZP/Ti₃SiC₂ MAX composites, which can potentially be used as new cutting tool materials and to achieve easy machinability through computer numerical control (CNC)-based drilling operations. Here, the thermal conductivity behavior, CNC machinability, and microstructural characteristics of the as-received 12Ce-TZP and 12Ce-TZP/<i>x</i>Ti₃SiC₂ MAX; <i>x</i> = 0.5 and 2.5 wt.% composites sintered at 1550°C for 2 h were investigated. Based on the overall results, the thermal conductivity values of 12Ce-TZP/2.5 wt.% Ti₃SiC₂ MAX composites were calculated to be 1.54±0.04 W/mˑK at 1000°C and 2.17±0.03 W/mˑK at ambient temperature. These newly designed composites, incorporating Ti₃SiC₂ at 0.5 and 2.5 wt.% in the 12Ce-TZP matrix, were successfully drilled into circular holes using CNC. Considering the detailed results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), the formation of interlocking and intergranular network structures between 12Ce-TZP grains and the Ti₃SiC₂ phase plays a key role in achieving good machinability characteristics for the newly designed 12Ce-TZP/2.5 wt.% Ti₃SiC₂ MAX composites. We expect that the results presented here will open a new door for converting non-machinable ceramics to a machinable form.</p>