The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 16501 | Onenos | £ 114,882,834 | |
| 16502 | oneone | £ 18,206,569 | |
| 16503 | Oner | £ 10,516,756 | |
| 16504 | Onerous | £ 40,516,043 | |
| 16505 | OneStopEnvelopeShoppe | £ -38,952 | |
| 16506 | Onetical | £ 5,502,381 | |
| 16507 | Onioninc | £ -43,613 | |
| 16508 | Onions | £ 56,031,337 | |
| 16509 | ONLINE GAMES | £ 120,242,830 | |
| 16510 | online games. | £ 167,252,652 | |
| 16511 | Only 50k | £ 120,794,156 | |
| 16512 | Only Bombs Allowed | £ 57,741,277 | |
| 16513 | Only Fools and Horses | £ 859,719,219 | |
| 16514 | Only Grans | £ 52,787,706 | |
| 16515 | only me | £ 50,000 | |
| 16516 | only me inc | £ 133,078,068 | |
| 16517 | OnlyDollars | £ 929,042 | |
| 16518 | OnlyMoney | £ 4,556,121 | |
| 16519 | OnlyProfits | £ 5,059,024 | |
| 16520 | OnlyStocks | £ 4,382,795 | |
| 16521 | Onomatopoeias | £ 939,660 | |
| 16522 | Onshore Money | £ 104,918,400 | |
| 16523 | Onslaught | £ 173,341,068 | |
| 16524 | Ontara | £ 79,736,570 | |
| 16525 | Ontario | £ 159,783,223 | |
| 16526 | ontheblock | £ 6,402,837 | |
| 16527 | Onyx | £ 429,592 | |
| 16528 | OO7 | £ 24,682,212 | |
| 16529 | Oodnadatta | £ 2,300,000 | |
| 16530 | Ooglaigh na Heireann | £ 240,713,877 | |
| 16531 | oohyeaa | £ 50,844,745 | |
| 16532 | Oolacile-01 | £ 3,643,194 | |
| 16533 | oOoOo | £ 82,717,145 | |
| 16534 | oooooo | £ 5,505,528 | |
| 16535 | OOOoooOOO | £ 614,697 | |
| 16536 | oooPPPooo | £ -53,065 | |
| 16537 | oops | £ 965,477 | |
| 16538 | ooz | £ 320,966,832 | |
| 16539 | Opal Opal | £ 5,502,194 | |
| 16540 | Opec | £ 1,574,677,165 | |
| 16541 | Opel Dire | £ 5,505,993 | |
| 16542 | Open AI | £ 50,000 | |
| 16543 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 16544 | Open Goal | £ 2,425,721 | |
| 16545 | Openhammer | £ 38,675,735 | |
| 16546 | Opera House | £ 123,137,933 | |
| 16547 | operating systems | £ 46,331,716 | |
| 16548 | Operation Centerboard | £ 45,661,943 | |
| 16549 | OPERATION SEALION | £ 10,353,786 | |
| 16550 | OPERATION SEALION 2 | £ 5,504,218 | |
| 16551 | Ophthalmology | £ 45,575,639 | |
| 16552 | Opinion | £ 389,953,431 | |
| 16553 | OPiuM | £ 115,856,941 | |
| 16554 | Oppa Gangnam Style | £ 65,242,420 | |
| 16555 | Oppenheim | £ 51,959,450 | |
| 16556 | Oppenheimer | £ 1,424,302 | |
| 16557 | Oppertunity | £ 512,316,834 | |
| 16558 | Opportunities | £ 58,183,350 | |
| 16559 | Opportunity | £ 11,354,079 | |
| 16560 | Opposition | £ 761,831,311 | |
| 16561 | Oppression | £ 416,055,267 | |
| 16562 | OpRedStripe | £ 39,676,062 | |
| 16563 | optics | £ 57,286,889 | |
| 16564 | Optimal Flames | £ 175,592,178 | |
| 16565 | Optimum Nutrition | £ -3,018,246 | |
| 16566 | Optimus Inc. | £ -2,482,292 | |
| 16567 | Options | £ 84,494,650 | |
| 16568 | Options Trading | £ 15,395,474 | |
| 16569 | Opus Dei | £ 1,713,492,650 | |
| 16570 | opus technology | £ 35,372,824 | |
| 16571 | Or Fords | £ 45,497,219 | |
| 16572 | Oracle | £ 5,067,108 | |
| 16573 | Orakos | £ 9,653,572 | |
| 16574 | Orange | £ 24,725,264 | |
| 16575 | Orange Aftershock | £ 67,681,186 | |
| 16576 | Orange Castle | £ 615,362 | |
| 16577 | Orange County | £ 4,910,507 | |
| 16578 | Orange Creatine | £ 6,196,167 | |
| 16579 | Orange Jelly | £ 6,594,926 | |
| 16580 | Orange Jooze | £ 1,261,621 | |
| 16581 | Orange Jooze 3 | £ 50,000 | |
| 16582 | Orange Jooze2 | £ 795,888 | |
| 16583 | Orange Jooze4 | £ 50,000 | |
| 16584 | Orange Jooze5 | £ 50,000 | |
| 16585 | Orange Mango | £ 9,110,398 | |
| 16586 | Orange Paint | £ 97,288,036 | |
| 16587 | Oranginal | £ 4,103,756 | |
| 16588 | oranje | £ 4,966,784 | |
| 16589 | Orbital | £ 54,539,946 | |
| 16590 | Orbital Bombardment | £ 1,279,471,445 | |
| 16591 | Orbital Mechanics | £ 181,007,918 | |
| 16592 | Orbital Oasis | £ 61,220,273 | |
| 16593 | Orchids R Us Ltd | £ 39,331,588 | |
| 16594 | orcs | £ 2,521,634,731 | |
| 16595 | Orcustra | £ 702,800 | |
| 16596 | Order | £ 176,233,665 | |
| 16597 | Order Flow | £ 121,681,973 | |
| 16598 | Orders | £ 27,738,927 | |
| 16599 | Ordinance | £ 12,412,156 | |
| 16600 | ordinary matter | £ 330,372,055 | |
