Abstract In this study, a novel high‐entropy carbide‐based ceramic cutting tool was developed. The cutting performance of three kinds of high‐entropy carbide‐based ceramic tools with different mechanical properties for the ISO C45E4 steel were evaluated. Although the pure (Ti 0.2 Zr 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )C 0.8 ceramic cutting tool exhibited the highest hardness of 25.06 ± 0.32 GPa, the cutting performance was poor due to the chipping and catastrophic failure caused by the low toughness (2.25 ± 0.27 MPa m 1/2 ). The (Ti 0.2 Zr 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )C 0.8 –15 vol% cobalt cutting tool with highest fracture toughness (6.37 ± 0.24 MPa m 1/2 ) and lowest hardness (17.29 ± 0.79 GPa) showed the medium cutting performance due to the low wear resistance caused by the low hardness. The (Ti 0.2 Zr 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )C 0.8 –7.7 vol% cobalt cutting tool showed the longest effective cutting life of ∼67 min due to the high wear resistance and chipping resistance caused by the high hardness (21.05 ± 0.72 GPa), high toughness (5.35 ± 0.51 MPa m 1/2 ), and fine grain size (0.60 ± 0.15 μm). The wear mechanisms of the cobalt‐containing (Ti 0.2 Zr 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )C 0.8 ceramic cutting tools included adhesive wear and abrasive wear and oxidative wear. This research indicated that the high‐entropy carbide‐based ceramics with high hardness and high toughness have potential use in the field of cutting tool application.