| Abbreviation | Definition |
|---|---|
| OLN | Obnoxious Little Nut |
| OLOY | Only Losers Obey Yolo |
| OLQ | Obnoxious Little Queer |
| OLZ | One Legged Zebra |
| OM | Obnoxious Moron |
| OMAHA | Oh My Another Hopeless Audible |
| OMC | Official Millionaires Club |
| OME | Old Man Emu |
| OMEN | Old Mean Evil Nasty |
| OMG | Octopus Makes Goop |
| OMG | Oh My Gourd |
| OMG | Oh my, gerbils |
| OMG | Oh, My Gabe |
| OMG | Oh, My Gluesticks! |
| OMG | Old Man Gloom |
| OMG | Oppose Microsoft Group |
| OMG | Orange Mice Grinds |
| OMG | Ostriches Mooning George |
| OMGF | Oh, My GodFather |
| OMGHHKP | Oh My God Hurry Happy Kind People |