The following list shows all the companies that are in the game.
| Companies List | |||
| Pos. | Company Name | Awards | Total Worth |
| 16301 | OneStopEnvelopeShoppe | £ -38,952 | |
| 16302 | Onetical | £ 5,502,381 | |
| 16303 | Onioninc | £ -43,613 | |
| 16304 | Onions | £ 56,031,337 | |
| 16305 | ONLINE GAMES | £ 120,242,830 | |
| 16306 | online games. | £ 167,252,652 | |
| 16307 | Only 50k | £ 120,794,156 | |
| 16308 | Only Bombs Allowed | £ 57,741,277 | |
| 16309 | Only Fools and Horses | £ 859,719,219 | |
| 16310 | Only Grans | £ 22,170,777 | |
| 16311 | only me | £ 50,000 | |
| 16312 | only me inc | £ 133,078,068 | |
| 16313 | OnlyDollars | £ 929,042 | |
| 16314 | OnlyMoney | £ 4,556,121 | |
| 16315 | OnlyProfits | £ 5,059,024 | |
| 16316 | OnlyStocks | £ 4,382,795 | |
| 16317 | Onomatopoeias | £ 939,660 | |
| 16318 | Onshore Money | £ 104,918,400 | |
| 16319 | Onslaught | £ 143,496,124 | |
| 16320 | Ontara | £ 79,736,570 | |
| 16321 | Ontario | £ 159,783,223 | |
| 16322 | ontheblock | £ 6,402,837 | |
| 16323 | Onyx | £ 429,592 | |
| 16324 | OO7 | £ 24,682,212 | |
| 16325 | Oodnadatta | £ 2,300,000 | |
| 16326 | Ooglaigh na Heireann | £ 240,713,877 | |
| 16327 | oohyeaa | £ 50,844,745 | |
| 16328 | Oolacile-01 | £ 3,643,194 | |
| 16329 | oOoOo | £ 82,717,145 | |
| 16330 | oooooo | £ 5,505,528 | |
| 16331 | OOOoooOOO | £ 614,697 | |
| 16332 | oooPPPooo | £ -53,065 | |
| 16333 | oops | £ 965,477 | |
| 16334 | ooz | £ 320,966,832 | |
| 16335 | Opal Opal | £ 5,502,194 | |
| 16336 | Opec | £ 1,574,677,165 | |
| 16337 | Opel Dire | £ 5,505,993 | |
| 16338 | Open AI | £ 50,000 | |
| 16339 | OpEn FoR BuIsNeSs | £ 5,785,269 | |
| 16340 | Open Goal | £ 2,425,721 | |
| 16341 | Openhammer | £ 27,454,719 | |
| 16342 | Opera House | £ 123,137,933 | |
| 16343 | operating systems | £ 49,122,152 | |
| 16344 | Operation Centerboard | £ 45,661,943 | |
| 16345 | OPERATION SEALION | £ 10,353,786 | |
| 16346 | OPERATION SEALION 2 | £ 5,504,218 | |
| 16347 | Ophthalmology | £ 45,575,639 | |
| 16348 | Opinion | £ 389,953,431 | |
| 16349 | OPiuM | £ 115,856,941 | |
| 16350 | Oppa Gangnam Style | £ 65,242,420 | |
| 16351 | Oppenheim | £ 51,959,450 | |
| 16352 | Oppenheimer | £ 1,424,302 | |
| 16353 | Oppertunity | £ 512,316,834 | |
| 16354 | Opportunities | £ 58,183,350 | |
| 16355 | Opportunity | £ 11,354,079 | |
| 16356 | Opposition | £ 761,831,311 | |
| 16357 | Oppression | £ 416,055,267 | |
| 16358 | OpRedStripe | £ 39,676,062 | |
| 16359 | optical | £ 664,617,889 | |
| 16360 | optics | £ 57,286,889 | |
| 16361 | Optimal Flames | £ 175,592,178 | |
| 16362 | Optimum Nutrition | £ -3,018,246 | |
| 16363 | Optimus Inc. | £ -2,482,292 | |
| 16364 | Options | £ 84,494,650 | |
| 16365 | Options Trading | £ 15,395,474 | |
| 16366 | Opus Dei | £ 1,581,435,963 | |
| 16367 | opus technology | £ 35,372,824 | |
| 16368 | Or Fords | £ 46,884,912 | |
| 16369 | Oracle | £ 5,067,108 | |
| 16370 | Orakos | £ 9,653,572 | |
| 16371 | Orange | £ 24,725,264 | |
| 16372 | Orange Aftershock | £ 67,681,186 | |
| 16373 | Orange Castle | £ 615,362 | |
| 16374 | Orange County | £ 4,910,507 | |
| 16375 | Orange Creatine | £ 6,196,167 | |
| 16376 | Orange Jelly | £ 6,594,926 | |
| 16377 | Orange Jooze | £ 1,261,621 | |
| 16378 | Orange Jooze 3 | £ 50,000 | |
| 16379 | Orange Jooze2 | £ 795,888 | |
| 16380 | Orange Jooze4 | £ 50,000 | |
| 16381 | Orange Jooze5 | £ 50,000 | |
| 16382 | Orange Mango | £ 3,349,551 | |
| 16383 | Orange Paint | £ 97,288,036 | |
| 16384 | Oranginal | £ 4,103,756 | |
| 16385 | oranje | £ 4,966,784 | |
| 16386 | Orbital | £ 54,539,946 | |
| 16387 | Orbital Bombardment | £ 1,279,471,445 | |
| 16388 | Orbital Mechanics | £ 171,457,427 | |
| 16389 | Orbital Oasis | £ 61,220,273 | |
| 16390 | Orchids R Us Ltd | £ 39,331,588 | |
| 16391 | orcs | £ 2,521,634,731 | |
| 16392 | Orcustra | £ 702,800 | |
| 16393 | Order | £ 176,233,665 | |
| 16394 | Order Flow | £ 121,681,973 | |
| 16395 | Orders | £ 27,738,927 | |
| 16396 | Ordinance | £ 12,412,156 | |
| 16397 | ordinary matter | £ 329,475,963 | |
| 16398 | Oregon | £ 111,775,168 | |
| 16399 | OREO | £ 64,657,012 | |
| 16400 | Org | £ 18,286,924 | |
