The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 16401 | Oppenheim | £ 51,959,450 | |
| 16402 | Oppertunity | £ 512,316,834 | |
| 16403 | Opportunities | £ 58,183,350 | |
| 16404 | Opportunity | £ 11,354,079 | |
| 16405 | Opposition | £ 761,831,311 | |
| 16406 | Oppression | £ 416,055,267 | |
| 16407 | optics | £ 57,286,889 | |
| 16408 | Optimal Flames | £ 175,592,178 | |
| 16409 | Optimum Nutrition | £ -3,018,246 | |
| 16410 | Optimus Inc. | £ -2,482,292 | |
| 16411 | Options | £ 84,494,650 | |
| 16412 | Options Trading | £ 15,395,474 | |
| 16413 | Opus Dei | £ 1,714,492,650 | |
| 16414 | opus technology | £ 35,372,824 | |
| 16415 | Or Fords | £ 44,797,058 | |
| 16416 | Oracle | £ 5,067,108 | |
| 16417 | Orakos | £ 9,653,572 | |
| 16418 | Orange | £ 24,725,264 | |
| 16419 | Orange Aftershock | £ 67,681,186 | |
| 16420 | Orange Castle | £ 615,362 | |
| 16421 | Orange County | £ 4,910,507 | |
| 16422 | Orange Creatine | £ 6,196,167 | |
| 16423 | Orange Jelly | £ 6,594,926 | |
| 16424 | Orange Jooze | £ 1,261,621 | |
| 16425 | Orange Jooze 3 | £ 50,000 | |
| 16426 | Orange Jooze2 | £ 795,888 | |
| 16427 | Orange Jooze4 | £ 50,000 | |
| 16428 | Orange Jooze5 | £ 50,000 | |
| 16429 | Orange Paint | £ 97,288,036 | |
| 16430 | Oranginal | £ 4,103,756 | |
| 16431 | oranje | £ 4,966,784 | |
| 16432 | Orbital | £ 54,539,946 | |
| 16433 | Orbital Bombardment | £ 1,279,471,445 | |
| 16434 | Orbital Mechanics | £ 187,727,428 | |
| 16435 | Orbital Oasis | £ 61,220,273 | |
| 16436 | Orchids R Us Ltd | £ 39,331,588 | |
| 16437 | orcs | £ 2,521,634,731 | |
| 16438 | Orcustra | £ 702,800 | |
| 16439 | Order | £ 176,233,665 | |
| 16440 | Order Flow | £ 121,681,973 | |
| 16441 | Ordinance | £ 12,412,156 | |
| 16442 | ordinary matter | £ 331,548,976 | |
| 16443 | Oregon | £ 119,400,599 | |
| 16444 | OREO | £ 64,657,012 | |
| 16445 | Org | £ 18,286,924 | |
| 16446 | Organic Fruits and Veggy | £ 23,175,728 | |
| 16447 | Organics Ltd | £ 105,054,559 | |
| 16448 | Organised | £ 41,524,522 | |
| 16449 | Organised Crime | £ 17,216,443 | |
| 16450 | Organised.net | £ 55,489,672 | |
| 16451 | Organized Crime | £ 62,808,878 | |
| 16452 | Orgia Co. | £ 4,887,593 | |
| 16453 | Orgy | £ 6,138,687,187 | |
| 16454 | Origin | £ 1,771,884,318 | |
| 16455 | Original 16 | £ 174,342,608 | |
| 16456 | Original Gangster | £ 120,299,845 | |
| 16457 | Original Sin | £ 144,878,801 | |
| 16458 | Original Taste | £ 47,942,688 | |
| 16459 | Original Thoughts | £ 95,987,861 | |
| 16460 | Originality | £ 2,404,207,968 | |
| 16461 | Origins | £ 63,035,912 | |
| 16462 | Orino | £ 56,346,103 | |
| 16463 | Orion | £ 47,648,728 | |
| 16464 | Orion. | £ 374,172,630 | |
| 16465 | Orleans | £ 105,660,211 | |
| 16466 | orm | £ 2,684,322,281 | |
| 16467 | orming | £ 84,475,985 | |
| 16468 | Ornate | £ -8,047,867 | |
| 16469 | Orome Aldaron | £ 1,531,184,473 | |
| 16470 | OronzoMafia | £ 5,474,161 | |
| 16471 | Orphans Court | £ 297,981,744 | |
| 16472 | Orpheus | £ 288,236,792 | |
| 16473 | Orphic Co. | £ 4,423,125 | |
| 16474 | Orquinox Co. | £ 1,119 | |
| 16475 | Orricks IT Services | £ 15,082,611 | |
| 16476 | Ortcaj | £ 77,296,813 | |
| 16477 | Orthanc Inc. | £ 147,448,563 | |
| 16478 | Osaka | £ 5,504,057 | |
| 16479 | Osakin | £ 6,161,131 | |
| 16480 | Osbourne | £ 1,744,973 | |
| 16481 | osca-websites | £ 9,181,996 | |
| 16482 | Oscar Meyer | £ 5,773,809 | |
| 16483 | Oscars Emporium | £ 148,690,217 | |
| 16484 | Oscillation | £ 3,001,978 | |
| 16485 | Oscorp Industries | £ 179,374 | |
| 16486 | OSHA | £ 4,552,420 | |
| 16487 | OSHA Six Flags | £ 5,346,082 | |
| 16488 | Osipolis | £ 16,660,041 | |
| 16489 | Osiris | £ 225,126,101 | |
| 16490 | osiris666 | £ -1,880,407 | |
| 16491 | osiris6971 | £ 50,840,965 | |
| 16492 | Oslo | £ 9,880,014 | |
| 16493 | Osmosis | £ 41,633,292 | |
| 16494 | Osprey Close | £ 53,590,765 | |
| 16495 | Othello | £ 79,511,406 | |
| 16496 | Other Companies | £ 3,621,439 | |
| 16497 | other comps | £ 286,021,008 | |
| 16498 | Other People | £ 12,169,340 | |
| 16499 | Others | £ 26,039,960 | |
| 16500 | Others sometimes | £ 65,359,099 | |
