| Acronym | Definition |
|---|
| OOo | Openoffice.org (Sun Microsystems) |
| OOo | One on One |
| OOo | Out Of Order (execution) |
| OOo | Odd One Out |
| OOo | Oscuro's Oblivion Overhaul (gaming, The Elder Scrolls: Oblivion IV mod) |
| OOo | Oil of Olay (cosmetic) |
| OOo | Open Office Org |
| OOo | Out of Order |
| OOo | On Our Own |
| OOo | Out Of Office |
| OOo | Out of the Ordinary |
| OOo | Optical Optical Optical (telecommunications switching) |
| OOo | Of Obscure Origin |
| OOo | Outwit Outplay Outlast (Survivor TV Show) |
| OOo | Out Of Option |
| OOo | Obschestvo S Ogranichennoi Otvetstvennost'yu (Russian: Limited Liability Company, Llc) |
| OOo | Object-Oriented Organization |
| OOo | Object Oriented Operation (TMN) |
| OOo | Overly Officious Official (sports officiating) |