The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 15201 | OO7 | £ 6,532,200 | |
| 15202 | Ooglaigh na Heireann | £ 240,713,877 | |
| 15203 | oohyeaa | £ 50,844,745 | |
| 15204 | Oolacile-01 | £ 3,643,194 | |
| 15205 | oOoOo | £ 16,011,722 | |
| 15206 | oooooo | £ 5,505,528 | |
| 15207 | OOOoooOOO | £ 614,697 | |
| 15208 | oooPPPooo | £ -53,065 | |
| 15209 | oops | £ 965,477 | |
| 15210 | ooz | £ 320,966,832 | |
| 15211 | Opal Opal | £ 5,502,194 | |
| 15212 | Opec | £ 1,286,857,554 | |
| 15213 | Opel Dire | £ 5,505,993 | |
| 15214 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 15215 | Opera House | £ 123,137,933 | |
| 15216 | OPERATION SEALION | £ 10,353,786 | |
| 15217 | OPERATION SEALION 2 | £ 5,504,218 | |
| 15218 | Operations | £ 8,189,228 | |
| 15219 | Ophthalmology | £ 45,575,639 | |
| 15220 | opiates | £ 13,739,770 | |
| 15221 | Opinion | £ 389,953,431 | |
| 15222 | OPiuM | £ 115,856,941 | |
| 15223 | Oppa Gangnam Style | £ 65,242,420 | |
| 15224 | Oppenheim | £ 51,959,450 | |
| 15225 | Oppertunity | £ 512,316,834 | |
| 15226 | Opportunity | £ 11,354,079 | |
| 15227 | Opposition | £ 761,831,311 | |
| 15228 | Oppression | £ 416,055,267 | |
| 15229 | OpRedStripe | £ 39,676,062 | |
| 15230 | optical | £ 491,833,848 | |
| 15231 | Optimal Flames | £ 172,997,462 | |
| 15232 | Optimum Nutrition | £ -3,018,246 | |
| 15233 | Optimus Inc. | £ -2,482,292 | |
| 15234 | Options | £ 84,494,650 | |
| 15235 | Options Trading | £ 15,395,474 | |
| 15236 | Opus Dei | £ 837,716,828 | |
| 15237 | opus technology | £ 35,372,824 | |
| 15238 | Oracle | £ 5,067,108 | |
| 15239 | Orakos | £ 9,653,572 | |
| 15240 | Orang | £ 46,959,797 | |
| 15241 | Orange | £ 24,725,264 | |
| 15242 | Orange Aftershock | £ 67,681,186 | |
| 15243 | Orange Castle | £ 615,362 | |
| 15244 | Orange County | £ 4,910,507 | |
| 15245 | Orange Creatine | £ 6,196,167 | |
| 15246 | Orange Inc. | £ 1,716,053 | |
| 15247 | Orange Jelly | £ 6,594,926 | |
| 15248 | Orange Jooze | £ 1,261,621 | |
| 15249 | Orange Jooze 3 | £ 50,000 | |
| 15250 | Orange Jooze2 | £ 795,888 | |
| 15251 | Orange Jooze4 | £ 50,000 | |
| 15252 | Orange Jooze5 | £ 50,000 | |
| 15253 | Orange Juice | £ 23,922,208 | |
| 15254 | Orange Paint | £ 97,288,036 | |
| 15255 | Oranginal | £ 4,103,756 | |
| 15256 | oranje | £ 4,966,784 | |
| 15257 | Orbital | £ 54,539,946 | |
| 15258 | Orbital Bombardment | £ 1,279,471,445 | |
| 15259 | Orbital Mechanics | £ 113,775,555 | |
| 15260 | Orchids R Us Ltd | £ 39,331,588 | |
| 15261 | orcs | £ 2,521,634,731 | |
| 15262 | Orcustra | £ 702,800 | |
| 15263 | Order | £ 176,233,665 | |
| 15264 | Order Flow | £ 121,681,973 | |
| 15265 | Orders | £ 27,738,927 | |
| 15266 | ordinary matter | £ 200,741,893 | |
| 15267 | Oregon | £ 111,775,168 | |
| 15268 | OREO | £ 64,657,012 | |
| 15269 | Org | £ 18,286,924 | |
| 15270 | Organic Beaver | £ 48,683,222 | |
| 15271 | Organic Fruits and Veggy | £ 23,175,728 | |
| 15272 | Organics Ltd | £ 105,054,559 | |
| 15273 | Organised Crime | £ 17,216,443 | |
| 15274 | Organized Crime | £ 62,808,878 | |
| 15275 | Orgia Co. | £ 4,887,593 | |
| 15276 | Orgy | £ 6,092,194,361 | |
| 15277 | Origin | £ 1,082,936,399 | |
| 15278 | Origin yartley | £ 37,041,694 | |
| 15279 | Original 16 | £ 174,342,608 | |
| 15280 | Original Sin | £ 144,878,801 | |
| 15281 | Originality | £ 1,720,806,838 | |
| 15282 | Origins | £ 63,035,912 | |
| 15283 | Orino | £ 56,346,103 | |
| 15284 | Orion | £ 47,648,728 | |
| 15285 | Orleans | £ 4,344,320 | |
| 15286 | orm | £ 2,347,774,758 | |
| 15287 | orming | £ 121,129,135 | |
| 15288 | Ornate | £ -8,047,867 | |
| 15289 | Orome Aldaron | £ 1,530,220,792 | |
| 15290 | OronzoMafia | £ 5,474,161 | |
| 15291 | Orphans Court | £ 297,981,744 | |
| 15292 | Orpheus | £ 110,452,289 | |
| 15293 | Orphic Co. | £ 4,423,125 | |
| 15294 | Orquinox Co. | £ 1,119 | |
| 15295 | Orricks IT Services | £ 15,082,611 | |
| 15296 | Ortcaj | £ 77,296,813 | |
| 15297 | Orthanc Inc. | £ 147,448,563 | |
| 15298 | Osaka | £ 5,504,057 | |
| 15299 | Osakin | £ 6,161,131 | |
| 15300 | Osbourne | £ 1,744,973 | |
