A grommet is a ring or edge strip inserted into a hole through thin material, typically a sheet of textile fabric, sheet metal or composite of carbon fiber, wood or honeycomb.

Grommets are generally flared or collared on each side to keep them in place, and are often made of metal, plastic, or rubber. They may be used to prevent tearing or abrasion of the pierced material or protection from abrasion of the insulation on the wire, cable, line being routed through the penetration, and to cover sharp edges of the piercing, or all of the above.

They are widely used for mounting shock-sensitive computer disk drives, particularly in equipment subject to vibration or jarring, but are not usually used with more robust modern drives.