| OmniComm Systems, Inc. (OMCM) OTCMKTS - OTC Markets | |
| OncoVista Innovative Therapies Inc (OVIT) OTCMKTS - OTC Markets | |
| OxySure Therapeutics Inc (OXYS) OTCMKTS - OTC Markets | |
| Onelife Technologies Corp (OLMM) OTCMKTS - OTC Markets | |
| Ovid Therapeutics Inc (OVID) NASDAQ - National Association of Securities Dealers Automated Quotations | |
| OCL Iron and Steel Limited (OISL) BSE - Bombay Stock Exchange | |
| Omax Autos Limited (OMAXAUTO) BSE - Bombay Stock Exchange | |
| OMEGA AG-SEEDS (PUNJAB) LTD. (OMEAG) BSE - Bombay Stock Exchange | |
| OnMobile Global Limited (ONMOBILE) BSE - Bombay Stock Exchange | |
| Opto Circuits (India) Ltd (OPTOCIRCUI) BSE - Bombay Stock Exchange | |
| Oracle Financial Services Software Ltd. (OFSS) BSE - Bombay Stock Exchange | |
| Orient Paper & Industries Limited (ORIENTPPR) BSE - Bombay Stock Exchange | |
| Oriental Bank of Commerce (ORIENTBANK) BSE - Bombay Stock Exchange | |
| Oswal Greentech Ltd (BINDALAGRO) NSE - National Stock Exchange of India | |
| OCL India Limited (OCL) NSE - National Stock Exchange of India | |