| Oliverlak (Oliverlak) | Angola | 0 | 0 | 0 |
| Oliver (obloom) | Hampshire Free State | 0 | 0 | 0 |
| Olle (Gilius) | Lund, Sweden | 0 | 0 | 0 |
| Olle (Opuspocus) | | 26 | 11 | 3 |
| OlyaBlumn (OlyaBlumn) | Украина | 0 | 0 | 0 |
| olyasmudova (olyasmudova) | Eritrea | 0 | 0 | 0 |
| OMsweetOM (OMsweetOM) | United States | 79 | 39 | 25 |
| on3xm (on3xm) | Chicago | 212 | 126 | 61 |
| onechadtall | Bay Area, CA | 0 | 0 | 0 |
| OneDarkCellar (Brewstein77) | Lehigh Valley, PA | 14 | 2 | 1 |
| OneFiver (onefiver) | | 105 | 50 | 28 |
| Onelouderash (onelouderash) | San Francisco, CA | 62 | 48 | 26 |
| Onlighost (Onlighost) | Yugoslavia | 0 | 0 | 0 |
| OnWisconsin (OnWisconsin) | Green Bay WI | 388 | 120 | 50 |
| oofaurotnorb (oofaurotnorb) | 2201 Ridges Road Baileys Harbor Wisconsin USA 54202 | 0 | 0 | 0 |