- OASA: Odisha Administration Service Association.
- OASA: Office of Academic and Student Affairs.
- OASA: Orissa Agricultural Services Association (Agriculture)
- OASA: Athens Urban Transport Organization.
- OASA: Office of the Assistant Secretary of the Army.
- OASA: Office of Alcoholism and Substance Abuse.
- OASA: Oregon Adult Soccer Association.
- OASA: Office of the Assistant Secretary for Administration.
