| Abbreviation | Definition |
|---|---|
| ACTC | Association for Core Texts and Courses |
| ACTD | Association of Courses in Theatre Design |
| ACTE | Association of Career and Technical Educators |
| ACTEA | Association for Christian Theological Education in Africa |
| ACTIT | Association Culturelle Des Travailleurs Immigres De Turquie |
| ACTIV | Association of Cardiac Technology In Victoria |
| ACTMD | Association Canadienne des Thérapeutes en Médecines Douces (French: Canadian Association of Therapis |
| ACTN | Association of Canadian Trauma Nurses |
| ACTO | Association for Counselling and Therapy Online |
| ACTO | Association of Clinical Trials Organizations |
| ACTO | Association of Coach Training Organizations |
| ACTO | Association of Container Train Operators |
| ACTP | Association des Clients des Transports Publics |
| ACTRA | American Cowboy Team Roping Association |
| ACTRA | American Cowboys Team Roping Association |
| ACTS | Association for Clinical and Translational Science |
| ACTT | Association of Cinematography and Television Technicians |
| ACU | Association of Commonwealth Universites |
| ACUA | Association of College and University Auditors |
| ACUA | Association of College University Auditors |