GROMMET AND WIRE HARNESS

A grommet includes a main body that fits into a through hole penetrating an attachment target in an axial direction to waterproof the through hole and that allows a wiring member to be inserted into an inner portion in the axial direction. The main body includes a plate-shaped portion extending in intersecting directions that intersect the axial direction so as to close at least a portion of the through hole, and a sound insulation wall portion having a sound insulation protrusion that protrudes from the plate-shaped portion in the axial direction so as to be formed in an annular or arc shape centered around a central axis in the axial direction.