45 companies · click a column to sort
| Company | Sector | Country | HQ | Founded | Listing |
|---|---|---|---|---|---|
 Oando | Oil, gas & power | Nigeria | Lagos | 1956 | — |
| OAOasis Agro Enterprise | Agriculture & food | Nigeria | Owerri | 2021 | — |
| OBOceanic Bank | Banking & finance | Nigeria | Abuja | 1990 | — |
 OCP Group | Mining & metals | Morocco | Casablanca | 1920 | — |
| OOOculus Operational Innovations | Construction & property | South Africa | Pretoria | 2009 | — |
| OOOffice of Transformation, Creativity and Innovation | Other sectors | Nigeria | Ikeja | 2009 | — |
| OLOhlthaver & List | Agriculture & food | Namibia | Windhoek | 1919 | — |
| OLOkFarm Limited | Agriculture & food | Nigeria | Lekki | 2018 | — |
 Ola South Africa | Other sectors | South Africa | Durban | 1992 | — |
 Olarm | Technology | South Africa | Cape Town | 2015 | — |
| OMOld Mutual | Banking & finance | South Africa | London | 1845 | Johannesburg Stock Exchange OMU |
| OGOlympic Group | Other sectors | Egypt | Nasr City | 1963 | — |
| OTOM TRANS | Other sectors | Algeria | Algiers | 1999 | — |
| OEOmar Effendi | Retail & consumer | Egypt | Cairo | 1856 | — |
| OIOmnium Immobilier Tunisien | Construction & property | Tunisia | Tunis | 1905 | — |
| OGONA Group | Agriculture & food | Morocco | Casablanca | 1934 | — |
 Onatel | Telecoms & internet | Burkina Faso | Ouagadougou | 1994 | — |
| ONOneDirectory | Technology | South Africa | — | 2011 | — |
 OneXGen Technology | Technology | Indonesia | Jakarta | 2023 | — |
 Ooredoo Algérie | Telecoms & internet | Algeria | Algiers | 2004 | — |
 Ooredoo Tunisia | Telecoms & internet | Tunisia | Tunis | 2002 | — |
| OFOpe Farms | Agriculture & food | Nigeria | Ikeja | 2014 | — |
| OPOpenwist | Technology | Kenya | Nairobi | 2026 | — |
| OUOpportunity Uganda Limited | Banking & finance | Uganda | Kampala | 1995 | — |
| OBOrabank Benin | Banking & finance | Benin | Cotonou | 1988 | — |
| OTOrabank Togo | Banking & finance | Togo | Lomé | 2003 | — |
| OROragroup | Banking & finance | Togo | Lomé | 1985 | Bourse Regionale Des Valeurs Mobilieres 69415031 |
 Orange Cameroon | Telecoms & internet | Cameroon | Douala | 2000 | — |
| Orange Centrafrique | Telecoms & internet | Central African Republic | Bangui | 2007 | — |
| Orange DRC | Telecoms & internet | Democratic Republic of the Congo | Kinshasa | 2001 | — |
| Orange DSL | Telecoms & internet | Egypt | Cairo | 2000 | — |
| Orange Mali | Telecoms & internet | Mali | Bamako | 2006 | — |
| Orange Morocco | Telecoms & internet | Morocco | Casablanca | 1999 | — |
| Orange Tunisia | Telecoms & internet | Tunisia | Tunis | 2009 | — |
| ONOrano Niger | Mining & metals | Niger | Niamey | 2006 | — |
 Orascom Construction Industries | Construction & property | Egypt | Cairo | 1950 | NL0010558797 |
| OROrderly | Retail & consumer | Nigeria | — | 2025 | — |
 Orient Bank | Banking & finance | Uganda | Kampala | 1993 | — |
| OEOrient Enterprises Limited | Agriculture & food | Kenya | Kiambu County | 2018 | — |
| OFOsiri Farm | Agriculture & food | Nigeria | Calabar | 2021 | — |
| OTOTEL Telecoms | Telecoms & internet | South Africa | Boksburg | 1995 | — |
| OOOtunba Owoyemi Adesina Enterprises | Construction & property | Nigeria | Ibadan | — | — |
 OUENZÉ | Retail & consumer | Democratic Republic of the Congo | Kinshasa | 2024 | — |
| OHOUTsurance Holdings | Banking & finance | South Africa | Centurion | 1998 | ZAE000314084 |
| OGOwners Group International | Banking & finance | Seychelles | — | 2004 | — |
Source: Wikidata (CC0)updated October 2026