| ATCA | Advanced Telecom Computer Architecture 
| Others |
| ATCA | Advanced Telecom Computing Architecture
| Others |
| ATCA | Advanced Telecommunication Computing Architecture
| Others |
| ATCA | Advanced Telecommunications Computer Architecture
| Others |
| ATCA | Advanced Telecommunications Computing Architecture
| Others |
| ATCA | African Tobacco Control Alliance
| Others |
| ATCA | Air Traffic Control Association
| Others |
| ATCA | Airedale Terrier Club of America
| Others |
| ATCA | Airline Training Center Arizona
| Others |
| ATCA | Aisin Technical Center of America
| Others |
| ATCA | Alaska Tobacco Control Alliance
| Others |
| ATCA | Alien Tort Claims Act
| Crime, Legal |
| ATCA | All Tripura Chess Association
| Others |
| ATCA | Allied Tactical Communications Agency
| Others |
| ATCA | Alternative Traditions in the Contemporary Arts
| Others |
| ATCA | American Theatre Critics Association
| Others |
| ATCA | Anti Terrorism Clarification Act
| Others |
| ATCA | Anti Theft Car Alarm
| Others |
| ATCA | Antique Telephone Collectors Association
| Others |
| ATCA | Antique Truck Club of America
| Others |
| ATCA | Association of Turkish Cypriots Abroad
| Others |
| ATCA | Australia Telescope Compact Array
| Others |