ACAS

ACAS or Acas may refer to:

Aviation

 * Airborne collision avoidance system, an International Civil Aviation Organization standard
 * Assistant Chief of the Air Staff, a senior appointment in the Royal Air Force

Other uses

 * Aboriginal Children's Advancement Society, an organization in New South Wales
 * Acas (Advisory, Conciliation and Arbitration Service), an independent non-departmental public body of the Government of the UK
 * Acâș, a commune in Satu Mare County, Romania
 * Acas District, Ocros, Peru
 * Associate in the Casualty Actuarial Society, a level of membership in the Casualty Actuarial Society
 * Assured Compliance Assessment Solution, a tool that automatically identifies configuration vulnerabilities on United States Department of Defense computer systems