Hoac, HOAc, or HOAC may refer to:

• An abbreviation of the chemical compound of Acetic acid.
• Historians of American Communism, a scholarly historical organization established in 1982.
• Hillingdon Outdoor Activity Centre, a water sports and activity centre based in Hillingdon, Middlesex, UK

• Business strike
• Business suit
• Business & Technology Education Council
• Business telephone system
• Business @ the Speed of Thought
• Business The Speed of Thought
• Business Times
• Business titles
• Business-to-business
• Business to business
• Business-to-business electronic commerce
• Business-to-employee electronic commerce
• Business-to-government
• Business-to-government e-commerce
• Business transformation
• Business Transformation
• Business valuation
• Business value
• Business Week
• Businessweek
• Business Week Magazine
• BusinessWeek Online
• Business Wire
• Businesswoman
• Busing