A blindfold (from Middle English blindfellen) is a garment, usually of cloth, tied to one's head to cover the eyes to disable the wearer's sight. It can be worn when the eyes are in a closed state and thus prevents the wearer from opening them. Even with the eyes open (as permitted by many blindfolds, especially those made of cloth), the user cannot see.

Covering a horse's eyes with a blindfold as a means of restraint. Most horses when blindfolded can be persuaded to load onto trailers which they refuse to do without the blindfold. Of some but more limited use in other species. A comparable device used in pigs, a bucket placed over the head, causes the pig to walk backwards. Provided the rear of the pig is pointed in the correct direction this is a worthwhile last try in getting a large pig to go where you want it to go.