| 8532 | Offender self-help organizations | |
| 3410 | Off-highway tracked vehicles (except construction, armoured military), manufacturing | |
| 2924 | Off-highway trucks, manufacturing | |
| 7414 | Office administration services | |
| 7010 | Office and desk space, rental service | |
| 2811 | Office and factory buildings, prefabricated metal, manufacturing | |
| 5239 | Office and school supplies (except furniture), retail | |
| 5110 | Office and store machinery and equipment, wholesale agents and brokers | |
| 5150 | Office and store machines, wholesale | |
| 7210 | Office automation system design services | |
| 7210 | Office automation, computer systems integration | |
| 7010 | Office building rental or leasing | |
| 4520 | Office buildings and complexes, construction | |
| 3610 | Office chair reupholstering and upholstery repair | |
| 7493 | Office cleaning service | |
| 5259 | Office coffee service | |
| 5239 | Office equipment stores selling primarily to other businesses | |
| 3610 | Office fixtures (except metal and wood), manufacturing | |
| 3610 | Office fixtures (except wood), manufacturing | |
| 3610 | Office furniture (except metal), manufacturing | |
| 6023 | Office furniture moving, used | |
| 7130 | Office furniture rental | |
| 3610 | Office furniture repair (except primarily of metal or plastic) | |
| 3610 | Office furniture repair, primarily of metal | |
| 3610 | Office furniture repair, primarily of plastic | |
| 5233 | Office furniture store selling primarily to other businesses but also selling to household consumers | |
| 3610 | Office furniture, metal, manufacturing | |
| 4530 | Office furniture, modular systems, installation | |
| 5150 | Office furniture, wholesale | |
| 3610 | Office furniture, wood, padded, upholstered, or plain, manufacturing | |
| 7491 | Office help supply service | |
| 7123 | Office machine rental (except computer and related electronic equipment) | |
| 7123 | Office machine rental and leasing (except computers) | |
| 7250 | Office machine repair, electrical | |
| 5150 | Office machines and equipment (except electronic data processing equipment), wholesale | |
| 7414 | Office management services | |
| 7421 | Office of engineers | |
| 2109 | Office paper (e.g., computer printer, photocopy, plain paper), cut sheet, made from purchased paper | |
| 2101 | Office paper (e.g., computer printer, photocopy, plain paper), made in paper mills | |
| 5239 | Office paper and supplies, retail | |