| Rattlesnake Mountain Observatory | Academic & Science |
| Revenue Management Operations | Business |
| Road Management Office | Business |
| Rocky Mountain Outfitters | Business |
| Rocky Mountain Orthodontics Inc. | Business |
| Regional Marketing Office | Business |
| Records Management Officer | Business |
| Resource Management Office | Business |
| Results Management Office | Business |
| Replication Management Objects | Business Management |
| Rental Management One | Business Management |
| Revenue Management and Optimization | Business Management |
| Rattlesnake Mountain Observer | Community |
| Rude Mechanical Orchestra | Community |
| Right Mode Operator | Computer Assembly Language |
| Reflectance Model | Computing |
| Refrigeration Machine Operator | General |
| Registered Market Operators | General |
| Repair Maintenance Operation | General |
| Royal Marine Office | General |
| Racing Motor Oil | General |
| Road Maintenance Officer | General |
| Road Management Objectives | General |
| Rocky Mountain Opels | General |
| Rocky Mountain Outfitter | General |
| Robert M Ochshorn | General |
| Rutherford MacDonald Olson | General |
| responsible managingofficer In order | General |
| Rocky Mountain Oils | General |
| Rayleigh Mens Own | General |
| ReichsMinister für die besetzten Ostgebiete (State Minister for the Occupied Eastern Territories) | Governmental |
| Resident Manager's Office | Governmental |
| Responsible Management Official | Governmental |
| RAMAKONA | Indian Railway Station |
| Rack Me Off | Internet |
| Responsible Managing Officer | Jobs |
| Regional Mathematics Olympiad | Maths |
| Registered Medical Officer | Medical |
| Resident Medical Officer | Medical |
| Regional Medical Officer | Medical |
| Responsible Medical Officer | Medical |
| Rock's Medical Outreach | Medical |
| Rocky Mountain Orthodontics | Medical |
| Regimental Medical Officer | Military and Defence |
| Requirements Management Office | Military and Defence |
| Risk Management Office | Military and Defence |
| Regional Marine Officer | Military and Defence |
| Range Management Office | Military and Defence |
| Regional Mathematical Olympiad | Regional |
| Regional Metrology Organizations | Regional |
| Records Management Office | Space Science |
