Education and academia

• Asia Theological Association
• American Translators Association
• Alberta Teachers' Association, Canada
• Ashcroft Technology Academy, Wandsworth, London, England
• Advanced Technologies Academy, a high school in Las Vegas, Nevada, USA

Science, technology, and medicine

• Anti-transglutaminase antibodies, in certain autoimmune diseases
• Advanced Technology Attachment (ATA/ATAPI ), an interface for computer storage devices
• Allen Telescope Array, for astronomical observations and search for extraterrestrial intelligence
• Analog telephony adapter, a device for connecting analog telephones to a Voice-over-IP system
• American Telemedicine Association

Transportation

• ATA Airlines, an American low-cost airline based in Indianapolis which operated from 1973 to 2008
• ATA Holdings, now Global Aero Logistics owner of ATA Airlines
• ATA Cruiser, a civil utility aircraft built by Adams-Toman Aircraft Co in the 1920s
• Air Transport Association of America
• Air Transport Auxiliary of the British Royal Air Force
• American Trucking Associations

Sport

• American Taekwondo Association
• Amateur Trapshooting Association
• Archery Trade Association

Modern culture

• Artists' Television Access a non-profit microcinema and art gallery in San Francisco
• Association of Talent Agents, Los Angeles
• American Topical Association, a philatelic organization
• ATA gene, Ancient Technology Activation Gene, in the Stargate science fiction TV series

Other

• Atlantic Treaty Association
• Áta, a village in Hungary
• Athens Trombone Association