A hood is a kind of headgear.

Today, hoods are generally soft headcoverings which form part of a larger garment (e.g. an overcoat, shirt or cloak; an exception is a rain hood which is not part of a larger garment). They can be pulled up over the head when needed, or left to hang down the back when not. They may also be detachable to turn a winter overcoat into a summer one, or may be designed to be folded or rolled into a small pocket in the neck of the garment when not in use.

Historically, hoods were either similar to modern hoods, often forming part of a cloak or cape, or a separate form of headgear. Soft hoods were worn by men under hats.

Women's hoods varied from close-fitting, soft headgear (e.g. snood) to stiffened, structured hoods (e.g. gable hood) or very large coverings made of material over a frame which fashionable women wore over towering wigs or hairstyles to protect them from the elements (e.g. calash).

A hood can also be headgear, possibly make-shift, e.g. a bag, that covers the whole head, with the result that the wearer can see little or nothing, like being blindfolded, and can also not be identified. It may be applied to a person who has been arrested or kidnapped. The practice is known as hooding.

A criminal may also wear a hood to prevent identification: in this case it has typically holes for the eyes.