To provide a grommet with excellent water cut property, facilitating work for inserting a wire harness body into a cylindrical portion of a grommet, and capable of protecting over the length as long as possible.

A grommet 20 includes a panel mounting part 22, and a cylindrical portion 30 provided in the panel mounting part 22 integrally therewith, and into which the wire harness body can be inserted. The cylindrical portion 30 is formed with annular groves 43 and 45 recessed in the outer peripheral side or the inner peripheral side, and a bellows-like portion 40 becoming a bellows by bending at the annular groves 43 and 45. In the bottom of the annular groves 43 and 45, grooves 43 and 45g further recessed with respect to the extension of both sides of the bottom are formed.