The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 12101 | OlDirty | £ 47,991,916 | |
| 12102 | oldschool | £ 50,536,236 | |
| 12103 | Oligarchy | £ 556,860,397 | |
| 12104 | Oligarchy inc. | £ 7,116,723 | |
| 12105 | olis | £ 91,036,818 | |
| 12106 | Oliver Cromwell | £ 220,112,740 | |
| 12107 | Oliver Queen | £ 56,107,912 | |
| 12108 | Olivers Imagination | £ 124,320,555 | |
| 12109 | Olrik | £ 22,147,425 | |
| 12110 | Olympia | £ 112,782,553 | |
| 12111 | olympic rings | £ 2,977,538,717 | |
| 12112 | Olympics | £ 5,508,747 | |
| 12113 | Olympus | £ 463,898,718 | |
| 12114 | Omega | £ 6,183,955 | |
| 12115 | Omega Indusries | £ 37,799 | |
| 12116 | OmegaFox Inc. | £ 1,266,634 | |
| 12117 | Omelette | £ 10,061,528 | |
| 12118 | Omerta | £ 1,007,186,123 | |
| 12119 | Omerta Inc. | £ 5,500,096 | |
| 12120 | Omni | £ 26,585,058 | |
| 12121 | Omni Consumer Products | £ -9,473,784 | |
| 12122 | omni4 | £ 1,185,151 | |
| 12123 | Omnia | £ 29,796,207 | |
| 12124 | on a stick | £ 13,410 | |
| 12125 | On all you Candyass | £ 69,045,286 | |
| 12126 | On Industries | £ 1,896,074 | |
| 12127 | On It | £ 59,533,659 | |
| 12128 | On My Mind | £ 87,748,385 | |
| 12129 | On The Fritz | £ 79,242,996 | |
| 12130 | on the road | £ 57,567,767 | |
| 12131 | Once Upon a Time | £ 24,760,937 | |
| 12132 | Once Were Warriors | £ 54,754,263 | |
| 12133 | one | £ 341,379,992 | |
| 12134 | One and a Half | £ 8,610,014,000 | |
| 12135 | One Company | £ 398,709,264 | |
| 12136 | One Eyed Three Leg Dog | £ 63,605,247 | |
| 12137 | One Hit Wonder | £ 30,087,678 | |
| 12138 | One Hundred Netro Bucks | £ 50,376,609 | |
| 12139 | One Insane Rastaman | £ 263,664,058 | |
| 12140 | one love | £ 3,838,898 | |
| 12141 | one man crying | £ 997,068,851 | |
| 12142 | One Mind | £ -5,139,455 | |
| 12143 | one of craze | £ 398,067,001 | |
| 12144 | One Piece | £ 11,282,781 | |
| 12145 | One Pound Fish | £ 1,584,921 | |
| 12146 | One Shot | £ 123,851,456 | |
| 12147 | One Silence | £ -4,074 | |
| 12148 | One to Many. | £ 4,976,234 | |
| 12149 | One United | £ 5,379,005 | |
| 12150 | one1 | £ 3,058,084 | |
| 12151 | OneNation | £ 45,456 | |
| 12152 | oneone | £ 18,206,569 | |
| 12153 | Oner | £ 10,516,756 | |
| 12154 | OneStopEnvelopeShoppe | £ -38,952 | |
| 12155 | Onion of Arabia | £ 11,458,256 | |
| 12156 | Onions | £ 56,031,337 | |
| 12157 | onions inc | £ 46,832,459 | |
| 12158 | ONLINE GAMES | £ 120,242,830 | |
| 12159 | Only Bombs Allowed | £ 57,741,277 | |
| 12160 | Only Fools and Horses | £ 832,610,954 | |
| 12161 | only me | £ 50,000 | |
| 12162 | only me inc | £ 133,078,068 | |
| 12163 | Onomatopoeias | £ 939,660 | |
| 12164 | Onshore Money | £ 104,918,400 | |
| 12165 | Ontara | £ 79,736,570 | |
| 12166 | Ontario | £ 85,260,376 | |
| 12167 | ontheblock | £ 6,402,837 | |
| 12168 | Onyx | £ 429,592 | |
| 12169 | OO7 | £ 5,508,861 | |
| 12170 | Ooglaigh na Heireann | £ 240,713,877 | |
| 12171 | oohyeaa | £ 50,844,745 | |
| 12172 | Oolacile-01 | £ 2,954,344 | |
| 12173 | oOoOo | £ 31,474,744 | |
| 12174 | oooooo | £ 5,505,528 | |
| 12175 | OOOoooOOO | £ 614,697 | |
| 12176 | oooPPPooo | £ -53,065 | |
| 12177 | oops | £ 965,477 | |
| 12178 | ooz | £ 320,966,832 | |
| 12179 | Opal Opal | £ 5,502,194 | |
| 12180 | Opec | £ 273,634,128 | |
| 12181 | Opel Dire | £ 5,505,993 | |
| 12182 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 12183 | Operation Racoon City | £ 4,748,173 | |
| 12184 | Operations | £ 8,189,228 | |
| 12185 | Ophthalmology | £ 45,575,639 | |
| 12186 | opiates | £ 10,578,986 | |
| 12187 | Opinion | £ 389,953,431 | |
| 12188 | OPiuM | £ 115,856,941 | |
| 12189 | Oppa Gangnam Style | £ 65,242,420 | |
| 12190 | Oppenheim | £ 51,959,450 | |
| 12191 | Oppertunity | £ 458,210,505 | |
| 12192 | Opportunity | £ 11,354,079 | |
| 12193 | Opposition | £ 761,831,311 | |
| 12194 | Oppression | £ 416,055,267 | |
| 12195 | optical | £ 324,272,679 | |
| 12196 | Optimal Flames | £ 168,931,399 | |
| 12197 | Optimum Nutrition | £ -3,018,246 | |
| 12198 | Optimus Inc. | £ -2,482,292 | |
| 12199 | Options | £ 84,494,650 | |
| 12200 | Opus Dei | £ 694,720,428 | |
