The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 12401 | oohyeaa | £ 50,844,745 | |
| 12402 | Oolacile-01 | £ 2,954,344 | |
| 12403 | oOoOo | £ 17,397,064 | |
| 12404 | oooooo | £ 5,505,528 | |
| 12405 | OOOoooOOO | £ 614,697 | |
| 12406 | oooPPPooo | £ -53,065 | |
| 12407 | oops | £ 965,477 | |
| 12408 | ooz | £ 320,966,832 | |
| 12409 | Opal Opal | £ 5,502,194 | |
| 12410 | Opec | £ 273,634,128 | |
| 12411 | Opel Dire | £ 5,505,993 | |
| 12412 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 12413 | Operation Racoon City | £ 4,748,173 | |
| 12414 | Operations | £ 8,189,228 | |
| 12415 | Ophthalmology | £ 45,575,639 | |
| 12416 | opiates | £ 10,578,986 | |
| 12417 | Opinion | £ 389,953,431 | |
| 12418 | OPiuM | £ 115,856,941 | |
| 12419 | Oppa Gangnam Style | £ 65,242,420 | |
| 12420 | Oppenheim | £ 51,959,450 | |
| 12421 | Oppertunity | £ 458,210,505 | |
| 12422 | Opportunity | £ 11,354,079 | |
| 12423 | Opposition | £ 761,831,311 | |
| 12424 | Oppression | £ 416,055,267 | |
| 12425 | optical | £ 431,050,369 | |
| 12426 | Optimal Flames | £ 168,931,399 | |
| 12427 | Optimum Nutrition | £ -3,018,246 | |
| 12428 | Optimus Inc. | £ -2,482,292 | |
| 12429 | Options | £ 84,494,650 | |
| 12430 | Opus Dei | £ 694,720,428 | |
| 12431 | opus technology | £ 35,372,824 | |
| 12432 | Oracle | £ 5,067,108 | |
| 12433 | Orakos | £ 5,484,841 | |
| 12434 | Orange | £ 24,725,264 | |
| 12435 | Orange Aftershock | £ 67,681,186 | |
| 12436 | Orange Castle | £ 615,362 | |
| 12437 | Orange Creatine | £ 6,196,167 | |
| 12438 | Orange Jelly | £ 6,594,926 | |
| 12439 | Orange Jooze | £ 1,261,621 | |
| 12440 | Orange Jooze 3 | £ 50,000 | |
| 12441 | Orange Jooze2 | £ 795,888 | |
| 12442 | Orange Jooze4 | £ 50,000 | |
| 12443 | Orange Jooze5 | £ 50,000 | |
| 12444 | Orange Juice | £ 6,035,607 | |
| 12445 | Orange Paint | £ 97,288,036 | |
| 12446 | Oranginal | £ 4,103,756 | |
| 12447 | oranje | £ 4,966,784 | |
| 12448 | Orbital | £ 54,539,946 | |
| 12449 | Orbital Bombardment | £ 1,130,573,207 | |
| 12450 | Orchids R Us Ltd | £ 39,331,588 | |
| 12451 | orcs | £ 2,521,634,731 | |
| 12452 | Orcustra | £ 702,800 | |
| 12453 | Order | £ 176,233,665 | |
| 12454 | Oregon | £ 111,775,168 | |
| 12455 | OREO | £ 64,657,012 | |
| 12456 | Org | £ 18,286,924 | |
| 12457 | Organic Beaver | £ 48,683,222 | |
| 12458 | Organics Ltd | £ 105,054,559 | |
| 12459 | Organised Crime | £ 17,216,443 | |
| 12460 | Organized Crime | £ 62,808,878 | |
| 12461 | Orgia Co. | £ 4,887,593 | |
| 12462 | Orgy | £ 4,311,652,261 | |
| 12463 | Origin yartley | £ 37,041,694 | |
| 12464 | Original 16 | £ 132,618,089 | |
| 12465 | Original Sin | £ 141,442,446 | |
| 12466 | Originality | £ 1,357,128,017 | |
| 12467 | Origins | £ 63,035,912 | |
| 12468 | Orion | £ 47,648,728 | |
| 12469 | orm | £ 413,783,803 | |
| 12470 | orming | £ 56,130,756 | |
| 12471 | OronzoMafia | £ 560,700 | |
| 12472 | Orphans Court | £ 18,746,350 | |
| 12473 | Orphic Co. | £ 4,423,125 | |
| 12474 | Orquinox Co. | £ 1,119 | |
| 12475 | Orricks IT Services | £ 15,082,611 | |
| 12476 | Ortcaj | £ 77,296,813 | |
| 12477 | Orthanc Inc. | £ 147,448,563 | |
| 12478 | Osaka | £ 5,504,057 | |
| 12479 | Osakin | £ 6,161,131 | |
| 12480 | osca-websites | £ 9,181,996 | |
| 12481 | Oscar Meyer | £ 5,773,809 | |
| 12482 | Oscorp Industries | £ 179,374 | |
| 12483 | OSHA Six Flags | £ 5,346,082 | |
| 12484 | Osipolis | £ 16,660,041 | |
| 12485 | Osiris | £ 225,126,101 | |
| 12486 | osiris666 | £ -1,880,407 | |
| 12487 | osiris6971 | £ 10,377,105 | |
| 12488 | Osmosis | £ 36,967,752 | |
| 12489 | Osprey Close | £ 53,590,765 | |
| 12490 | other comps | £ 171,572,056 | |
| 12491 | Other Reality | £ 4,518,202 | |
| 12492 | Otherones | £ 61,853,286 | |
| 12493 | Others | £ 26,039,960 | |
| 12494 | otherwil | £ 133,717 | |
| 12495 | otherwil2 | £ -34,567,223 | |
| 12496 | otherwil3 | £ 1,893,225 | |
| 12497 | otherwil4 | £ 4,826,025 | |
| 12498 | otherwil5 | £ 829,030 | |
| 12499 | Ottawa | £ 44,778,874 | |
| 12500 | Otto | £ 511,521,836 | |
