ACU may refer to:
Aviation Achutupo Airport in Guna Yala Region, Panama (IATA airport code ACU)
Computing Address computation unit, another name for address generation unit Automatic Client Upgrade, a facility within the Novell Open Enterprise Server
Education Abilene Christian University, a private Christian university in Abilene, Texas Ahram Canadian University, a private Egyptian university in of October City, Giza, Egypt Ajayi Crowther University, a private Christian university in Oyo, Oyo State Nigeria American City University in California or Wyoming Arizona Christian University, a private Christian university in Phoenix, Arizona Association of Commonwealth Universities, an association that represents over 480 universities from Commonwealth countries Australian Catholic University, Australia's only public Catholic university
Places Açu, municipality in the state of Rio Grande do Norte, Brazil Açu River, another name for the Piranhas River in Brazil Pariquera-Açu, a municipality in the state of São Paulo in Brazil Superporto do Açu, an industrial port complex in the state of Rio de Janeiro in Brazil
Organizations Acu Publishing, an imprint of the German group VDM Publishing devoted to the reproduction of Wikipedia content Altura Credit Union, a credit union in California American Conservative Union, a political lobbying group in the US Arab Customs Union, an organization under the Arab League for a Customs Union between Arab Members of the League Asian Clearing Union, an organization that settles international payments between member countries Assiniboine Credit Union, a credit union in Manitoba Auto-Cycle Union, the governing body of motorcycle sport in Great Britain American Coalition for Ukraine, a coalition of organizations that advocate for US support of Ukraine's defence and sovereignty
Military Army Combat Uniform, the combat uniform worn by the US Army, US Air Force, and US Space Force Assault Craft Unit, military units of the US Navy that specialize in amphibious warfare
Transportation Auto-Cycle Union, an officially recognised motorcycle governing body of the UK Automovil Club del Uruguay, a member of the Fédération Internationale de l'Automobile
Other uses ACU, a codon for the amino acid threonine ACU (Utrecht), a music venue in Utrecht, the Netherlands Armored Command Unit, the key unit in the RTS video game Supreme Commander Asian Currency Unit, a proposed unit of currency for Asia and Oceania Assassin's Creed Unity, a game set during the French Revolution