Ati

• Ati, Chad, a town in Chad
• Ati (tribe), a Negrito ethnic group in the Philippines
• Ati-Atihan Festival, an annual celebration held in the Philippines
• A queen of the fabled Land of Punt in Africa

As an acronym, ATI may refer to:

• ATI Technologies Inc., a technology company and a subsidiary of AMD
• ATI - Advisor Turning Independent, a financial advisor who currently works at a brokerage house thinking about starting his or her own brokerage service
• ATI - Aero Trasporti Italiani, a defunct Italian airline
• Acronis True Image, a software product
• Air Transport International, a charter cargo airline
• Allegheny Technologies, a steel company, ATI on the New York Stock Exchange
• Allied Telesis, a telecommunications company, formerly Allied Telesyn
• Auckland Technical Institute, now the Auckland University of Technology
• Ohio State University Agricultural Technical Institute
• Tunisian Internet Agency (Agence tunisienne d'Internet), a Tunisian ISP