A hat is an item of clothing worn on the head.

Hat or HAT could refer to:

• Help authoring tool
• histone acetyltransferase
• Human African Trypanosomiasis
• The mathematical symbol $\backslash hat\{x\}$ used to denote a unit vector.
• HAT a Greek airplane manufacturer
• H.A.T, Vietnamese female group.
• The Hat Game - variation of Cup

HAT (曖昧さ回避)