The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 15001 | One United | £ 5,379,005 | |
| 15002 | OneHATE | £ 67,247,345 | |
| 15003 | Onenos | £ 113,430,891 | |
| 15004 | oneone | £ 18,206,569 | |
| 15005 | Oner | £ 10,516,756 | |
| 15006 | ones for you | £ 3,880,111 | |
| 15007 | Onetical | £ 5,502,381 | |
| 15008 | Onions | £ 56,031,337 | |
| 15009 | ONLINE GAMES | £ 163,884,355 | |
| 15010 | online games. | £ 167,252,652 | |
| 15011 | Only 50k | £ 120,794,156 | |
| 15012 | Only Bombs Allowed | £ 57,741,277 | |
| 15013 | Only Fools and Horses | £ 859,719,219 | |
| 15014 | Only Grans | £ 122,787,706 | |
| 15015 | only me inc | £ 133,078,068 | |
| 15016 | OnlyDollars | £ 929,042 | |
| 15017 | OnlyMoney | £ 4,556,121 | |
| 15018 | OnlyProfits | £ 5,059,024 | |
| 15019 | OnlyStocks | £ 4,382,795 | |
| 15020 | Onomatopoeias | £ 939,660 | |
| 15021 | Onshore Money | £ 104,918,400 | |
| 15022 | Onslaught | £ 173,378,826 | |
| 15023 | Ontara | £ 79,736,570 | |
| 15024 | Ontario | £ 159,783,223 | |
| 15025 | ontheblock | £ 6,402,837 | |
| 15026 | OO7 | £ 24,682,212 | |
| 15027 | Ooglaigh na Heireann | £ 240,713,877 | |
| 15028 | oohyeaa | £ 50,844,745 | |
| 15029 | Oolacile-01 | £ 3,643,194 | |
| 15030 | oOoOo | £ 82,717,145 | |
| 15031 | oooooo | £ 5,505,528 | |
| 15032 | OOOoooOOO | £ 18,588,312 | |
| 15033 | oops | £ 965,477 | |
| 15034 | ooz | £ 320,966,832 | |
| 15035 | Opal Fruits | £ 4,866,553 | |
| 15036 | Opal Opal | £ 5,502,194 | |
| 15037 | Opec | £ 1,574,677,165 | |
| 15038 | Opel Dire | £ 5,505,993 | |
| 15039 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 15040 | OpenAI | £ 24,635,722 | |
| 15041 | Openhammer | £ 37,087,124 | |
| 15042 | Opera House | £ 123,137,933 | |
| 15043 | operating systems | £ 38,959,224 | |
| 15044 | Operation Centerboard | £ 45,661,943 | |
| 15045 | OPERATION SEALION | £ 10,353,786 | |
| 15046 | OPERATION SEALION 2 | £ 5,504,218 | |
| 15047 | Operations | £ 10,937,040 | |
| 15048 | Ophthalmology | £ 45,575,639 | |
| 15049 | Opinion | £ 389,953,431 | |
| 15050 | OPiuM | £ 115,856,941 | |
| 15051 | Oppa Gangnam Style | £ 65,242,420 | |
| 15052 | Oppenheim | £ 51,959,450 | |
| 15053 | Oppertunity | £ 512,316,834 | |
| 15054 | Opportunities | £ 58,183,350 | |
| 15055 | Opportunity | £ 11,354,079 | |
| 15056 | Opposition | £ 761,831,311 | |
| 15057 | Oppression | £ 416,055,267 | |
| 15058 | optics | £ 57,286,889 | |
| 15059 | Optimal Flames | £ 175,592,178 | |
| 15060 | Options | £ 84,494,650 | |
| 15061 | Options Trading | £ 15,395,474 | |
| 15062 | Opus Dei | £ 1,714,492,650 | |
| 15063 | opus technology | £ 35,372,824 | |
| 15064 | Or Fords | £ 46,761,990 | |
| 15065 | Oracle | £ 5,067,108 | |
| 15066 | Orakos | £ 9,653,572 | |
| 15067 | Orange | £ 24,725,264 | |
| 15068 | Orange Aftershock | £ 67,681,186 | |
| 15069 | Orange Castle | £ 615,362 | |
| 15070 | Orange County | £ 4,910,507 | |
| 15071 | Orange Creatine | £ 6,196,167 | |
| 15072 | Orange Jelly | £ 6,594,926 | |
| 15073 | Orange Jooze | £ 1,261,621 | |
| 15074 | Orange Jooze2 | £ 795,888 | |
| 15075 | Orange Paint | £ 97,288,036 | |
| 15076 | Oranginal | £ 4,103,756 | |
| 15077 | oranje | £ 4,966,784 | |
| 15078 | Orbital | £ 54,539,946 | |
| 15079 | Orbital Bombardment | £ 1,279,471,445 | |
| 15080 | Orbital Mechanics | £ 195,346,601 | |
| 15081 | Orbital Oasis | £ 61,220,273 | |
| 15082 | Orchids R Us Ltd | £ 39,331,588 | |
| 15083 | orcs | £ 2,521,634,731 | |
| 15084 | Orcustra | £ 702,800 | |
| 15085 | Order | £ 176,233,665 | |
| 15086 | Order Flow | £ 121,681,973 | |
| 15087 | Ordinance | £ 12,412,156 | |
| 15088 | ordinary matter | £ 331,796,471 | |
| 15089 | Oregon | £ 137,729,148 | |
| 15090 | OREO | £ 64,657,012 | |
| 15091 | Org | £ 18,286,924 | |
| 15092 | Organic Fruits and Veggy | £ 23,175,728 | |
| 15093 | Organics Ltd | £ 105,054,559 | |
| 15094 | Organised | £ 41,104,839 | |
| 15095 | Organised Crime | £ 17,216,443 | |
| 15096 | Organised.net | £ 55,489,672 | |
| 15097 | Organized Crime | £ 62,808,878 | |
| 15098 | Orgia Co. | £ 4,887,593 | |
| 15099 | Orgy | £ 6,636,104,393 | |
| 15100 | Origin | £ 1,772,327,457 | |
