| Acronym | Definition |
|---|
| OASA | Office of the Assistant Secretary of the Army |
| OASA | Office of Academic and Student Affairs |
| OASA | Office of Alcoholism and Substance Abuse |
| OASA | Office of Alcohol and Substance Abuse |
| OASA | Ontario Amateur Softball Association |
| OASA | Oklahoma Association of School Administrators |
| OASA | Orienteering Association of South Australia |
| OASA | Oregon Adult Soccer Association |
| OASA | Olympic and Amateur Sports Act |
| OASA | Organisation Against the Suffering of Animals (Denmark) |
| OASA | Older Adult Services Act |
| OASA | Office of the Assistant Secretary for Administration |
| OASA | Oklahoma Amateur Softball Association |
| OASA | Orthodontic Assistant School of Atlanta |
| OASA | Organismos Astikon Siginonion Athinon |
| OASA | OpenOffice.org Association for South Africa |
| OASA | Oregon Abuse Survivors and Advocates |
| OASA | Ontario Amputee Sports Association |
| OASA | Oregon Ambulatory Surgery Association |
| OASA | Office Administration Student Association |
| OASA | Observer's Assessment of Sedation and Anesthesia |
| OASA | Ottawa Area Superintendents' Association (Canada) |
| OASA | Office of the Assistant Secretary for Aging |