| 1 | ONS | One Airlines S.p.A. | IATA: IP, Callsign: Air Dreams, Founded in July 2013. Commenced operations in October 2013. Ceased operations on 24 June 2020. | RCH | AVCODES |
| 2 | ONS | OKLAHOMA NATIONAL STOCKYARDS | | | PWRC |
| 3 | ONS | Omnibus Nahverkehr Service GmbH | City: Peine | D | TRAFFIC |
| 4 | ONSC | OLD NINETY SEVEN (97) CONESTOGA CAR | | | SCAC3 |
| 5 | ONSE | ONTARIO STONE CORP | | | SCAC4 |
| 6 | ONSF | ON-SITE FUELS INC | | | SCAC4 |
| 7 | ONSI | O'NEAL STEEL INC | | | SCAC4 |
| 8 | ONSK | ON THE SPOT TRUCKING | | | SCAC4 |
| 9 | ONSL | ONEIDA STAR LINE INC | | | SCAC3 |
| 10 | ONSN | ONTARIO STONE CORPORATION | | | SCAC3 |
| 11 | ONSS | OCEAN SALES LTD | | | SCAC4 |
| 12 | ONST | OLD N STURDY TRUCKING CO | | | SCAC3 |
| 13 | ONST | OROZCO & SON TRANSPORTATION INC | | | SCAC4 |
| 14 | ONSW | OCEAN NAVIGATION SIX (6) CO LTD | | | SCAC4 |
| 15 | ONSX | Oglebay Norton Industrial Sands, Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 16 | ONSX | Oglebay Norton Industrial Sands, Inc. | Jul-00 | | NRHS |
| 17 | ONSX | OGLEBAY NORTON INDUSTRIAL SANDS, INC. | | | PWRC |
| 18 | ONSX | Oglebay Norton Industrial Sands | | | RSRV |
