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 See also Akas (disambiguation)