To provide a key rotor and a cylinder lock having the same which can prevent deposition of foreign materials in an operation area of a tumbler and eliminate the risk of adverse effects on operation of the tumbler.

A key rotor 3 comprises: a key insertion/extraction hole 30 for inserting/extracting a normal key K; and a tumbler holding hole which communicates with the key insertion/extraction hole 30 and movably holds a tumbler for key matching. The key insertion/extraction hole 30 has a protrusion 35 which is for removing foreign materials and fits into a key groove k of the normal key K, and the protrusion 35 for removing foreign materials is disposed on the key insertion side of the tumbler holding hole.