CUTTING INSERT, HOLDER, AND CUTTING TOOL

A cutting insert, a holder, and a cutting tool with which the cutting insert can be easily and stably mounted on the holder and a fabrication target object can be excellently fabricated are provided. A cutting tool 100 that is used to fabricate a fabrication target object W by cutting includes a holder 50 and a cutting insert 10 that is mounted on a distal end of the holder 50. The holder 50 includes an insert pocket 53 into which the cutting insert 10 is fitted and a stopper portion 61 that elastically locks the cutting insert 10 to be fitted into the insert pocket 53. The cutting insert 10 includes a cutting portion 11 including a cutting edge 13, a fitting portion 12 that is fitted into the insert pocket 53, and a lock portion 21 that is formed at the fitting portion 12 and is to be locked to the stopper portion 61 of the holder 50.