| M&RO | Maintenance and Refurbishment Operations 
| Others |
| MR&O | Marketing Requirements & Objectives
| Others |
| MRO | Machine Repair Operation
| Others |
| MRO | Machine Repair Option
| Others |
| MRO | Magdalena Ridge Observatory
| Others |
| MRO | Main Refinancing Operation
| Others |
| MRO | Maintenance and Repair Office
| Others |
| MRO | Maintenance Repair And Operating
| Others |
| MRO | Maintenance Repair And Operation
| Others |
| MRO | Maintenance Repair and Operational
| Others |
| MRO | Maintenance Repair and Operations
| Others |
| MRO | Maintenance Repair and Overhaul
| Others |
| MRO | Maintenance Repair Operating
| Others |
| MRO | Maintenance Repair Operations
| Others |
| MRO | Maintenance Repair Organization
| Others |
| MRO | Maintenance Repair Overhaul
| Others |
| MRO | Maintenance Repairs And Operational
| Others |
| MRO | Maintenance Repairs And Operations
| Others |
| MRO | Maintenance Resale and Operating
| Others |
| MRO | Maintenance, Repair and Overhaul
| Others, Business |
| MRO | Maintenance, Repair, and Operating
| Others |
| MRO | Maintenance, Repair, and Operations
| Others |
| MRO | Maintenance, Repair, and Overhaul
| Others |
| MRO | Malaysia Ragnarok Online
| Others |
| MRO | Malogabaritnyy Reaktivnyy Ognemet
| Others |
| MRO | Market Rent Only
| Others |
| MRO | Marketing Resource Organization
| Others |
| MRO | Mars Reconnaissance Orbiter
| Others |
| MRO | Mass Rescue Operation
| Others |
| MRO | Masterton, New Zealand
| Others |
| MRO | Material Release Order
| Others |
| MRO | Materiel Release Order
| Others |
| MRO | Mauritania Ouguiya
| Others |
| MRO | Mechanical Reproduction Order
| Others |
| MRO | Medicaid Rehab Option
| Others |
| MRO | Medical Records Officer
| Others |
| MRO | Medical Regulating Office
| Others |
| MRO | Medical Regulating Officer
| Others |
| MRO | Medical Review Officer
| Others |
| MRO | Medical Review Officers
| Others |
| MRO | Medium-Range Order
| Others |
| MRO | Memory Read Out
| Others |
| MRO | Method Resolution Order
| Others |
| MRO | Midwest Reliability Organization
| Others |
| MRO | Minature Rifle Optic
| Others |
| MRO | Miniature Rifle Optic
| Others |
| MRO | Minimum Realistic and Optimistic
| Others |
| MRO | Minneapolis Radiation Oncology
| Others |
| MRO | Mobile Repayment Option
| Others |
| MRO | Mooresville Regional Office
| Others |
| MRO | Motor Racing Outreach
| Others |
| MRO | Motorcycle Rights Organization
| Others |
| MRO | Motorcyclists Right Organization
| Others |
| MRO | Motorcyclists Rights Organization
| Others |
| MRO | Mount Rogers Outfitters
| Others |
| MRO | Mountains and Rivers Order
| Others |
| MRO | Multi Region Operation
| Others |
| MRO | Multi Region Option
| Others |
| MRO | Multidrug Resistant Organism
| Others |
| MRO | Muscle Receptor Organ
| Others |
| MRO | My Route Online
| Others |