The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 11701 | on the road | £ 58,360,757 | |
| 11702 | Once Upon a Time | £ 24,760,937 | |
| 11703 | Once Were Warriors | £ 54,754,263 | |
| 11704 | one | £ 341,379,992 | |
| 11705 | One and a Half | £ 7,972,296,208 | |
| 11706 | One Company | £ 403,147,572 | |
| 11707 | One Eyed Three Leg Dog | £ 63,605,247 | |
| 11708 | One Hit Wonder | £ 30,087,678 | |
| 11709 | One Insane Rastaman | £ 177,887,288 | |
| 11710 | one love | £ 3,838,898 | |
| 11711 | one man crying | £ 910,529,066 | |
| 11712 | One Mind | £ -5,139,455 | |
| 11713 | one of craze | £ 398,067,001 | |
| 11714 | One Piece | £ 11,282,781 | |
| 11715 | One Pound Fish | £ 1,584,921 | |
| 11716 | One Shot | £ 123,851,456 | |
| 11717 | One Silence | £ -4,074 | |
| 11718 | One to Many. | £ 4,976,234 | |
| 11719 | One United | £ 5,379,005 | |
| 11720 | one1 | £ 3,058,084 | |
| 11721 | OneNation | £ 45,456 | |
| 11722 | oneone | £ 18,206,569 | |
| 11723 | Oner | £ 10,516,756 | |
| 11724 | OneStopEnvelopeShoppe | £ -38,952 | |
| 11725 | Onion of Arabia | £ 11,458,256 | |
| 11726 | Onions | £ 56,031,337 | |
| 11727 | onions inc | £ 46,832,459 | |
| 11728 | ONLINE GAMES | £ 120,242,830 | |
| 11729 | Only Bombs Allowed | £ 57,741,277 | |
| 11730 | Only Fools and Horses | £ 252,842,613 | |
| 11731 | only me | £ 50,000 | |
| 11732 | only me inc | £ 133,078,068 | |
| 11733 | Onomatopoeias | £ 939,660 | |
| 11734 | Onshore Money | £ 104,918,400 | |
| 11735 | Ontara | £ 79,736,570 | |
| 11736 | Ontario | £ 85,260,376 | |
| 11737 | ontheblock | £ 6,402,837 | |
| 11738 | Onyx | £ 429,592 | |
| 11739 | Ooglaigh na Heireann | £ 240,713,877 | |
| 11740 | oohyeaa | £ 50,844,745 | |
| 11741 | Oolacile-01 | £ 2,954,344 | |
| 11742 | oOoOo | £ 60,043,338 | |
| 11743 | oooooo | £ 5,505,528 | |
| 11744 | OOOoooOOO | £ 614,697 | |
| 11745 | oooPPPooo | £ -53,065 | |
| 11746 | oops | £ 965,477 | |
| 11747 | ooz | £ 320,966,832 | |
| 11748 | Opal Opal | £ 5,502,194 | |
| 11749 | Opel Dire | £ 5,505,993 | |
| 11750 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 11751 | Operation Racoon City | £ 4,748,173 | |
| 11752 | Operations | £ 8,189,228 | |
| 11753 | Ophthalmology | £ 45,575,639 | |
| 11754 | opiates | £ 10,578,986 | |
| 11755 | Opinion | £ 389,953,431 | |
| 11756 | OPiuM | £ 115,856,941 | |
| 11757 | Oppa Gangnam Style | £ 65,242,420 | |
| 11758 | Oppenheim | £ 51,959,450 | |
| 11759 | Oppertunity | £ 458,210,505 | |
| 11760 | Opportunity | £ 11,354,079 | |
| 11761 | Opposition | £ 761,831,311 | |
| 11762 | Oppression | £ 416,055,267 | |
| 11763 | optical | £ 166,949,548 | |
| 11764 | Optimal Flames | £ 168,810,081 | |
| 11765 | Optimum Nutrition | £ -3,018,246 | |
| 11766 | Optimus Inc. | £ -2,482,292 | |
| 11767 | Options | £ 84,494,650 | |
| 11768 | Opus Dei | £ 694,720,428 | |
| 11769 | opus technology | £ 35,372,824 | |
| 11770 | Oracle | £ 5,067,108 | |
| 11771 | Orange | £ 24,725,264 | |
| 11772 | Orange Aftershock | £ 67,681,186 | |
| 11773 | Orange Castle | £ 615,362 | |
| 11774 | Orange Creatine | £ 6,196,167 | |
| 11775 | Orange Jelly | £ 6,594,926 | |
| 11776 | Orange Jooze | £ 1,261,621 | |
| 11777 | Orange Jooze 3 | £ 50,000 | |
| 11778 | Orange Jooze2 | £ 795,888 | |
| 11779 | Orange Jooze4 | £ 50,000 | |
| 11780 | Orange Jooze5 | £ 50,000 | |
| 11781 | Orange Paint | £ 97,288,036 | |
| 11782 | Oranginal | £ 4,103,756 | |
| 11783 | oranje | £ 4,966,784 | |
| 11784 | Orbital | £ 54,539,946 | |
| 11785 | Orbital Bombardment | £ 409,365,804 | |
| 11786 | Orchids R Us Ltd | £ 39,331,588 | |
| 11787 | orcs | £ 2,352,067,430 | |
| 11788 | Orcustra | £ 702,800 | |
| 11789 | Order | £ 176,233,665 | |
| 11790 | Oregon | £ 111,775,168 | |
| 11791 | OREO | £ 64,657,012 | |
| 11792 | Org | £ 18,286,924 | |
| 11793 | Organics Ltd | £ 105,054,559 | |
| 11794 | Organised Crime | £ 17,216,443 | |
| 11795 | Organized Crime | £ 62,808,878 | |
| 11796 | Orgia Co. | £ 4,887,593 | |
| 11797 | Orgy | £ 4,311,652,261 | |
| 11798 | Origin yartley | £ 37,041,694 | |
| 11799 | Original 16 | £ 132,618,089 | |
| 11800 | Original Sin | £ 141,442,446 | |
