| PTO | Pacific Theater of Operations 
| Others |
| PTO | Packet Timeout
| Others |
| PTO | Paid Time Off
| Others |
| PTO | Parent Teacher Organisation
| Others |
| PTO | Parent Teacher Organization
| Others |
| PTO | Parent-Teacher Organization
| Others |
| PTO | Participating Test Organization
| Others |
| PTO | Patella Tracking Orthosis
| Others |
| PTO | Patent and Trademark Office
| Others |
| PTO | Patent Trademark Office
| Others |
| PTO | Pato Branco, PR, Brazil
| Others |
| PTO | Payment Treatment and Operations
| Others |
| PTO | Pedagogy and Theatre of the Oppressed
| Others |
| PTO | Permanently Turned Off
| Others |
| PTO | Permeability Tuned Oscillator
| Others |
| PTO | Permission To Occupy
| Others |
| PTO | Permission To Operate
| Others |
| PTO | Personal Time Off
| Others |
| PTO | Photo Training Overseas
| Others |
| PTO | Place Time Opportunity
| Others |
| PTO | Please Take Off
| Others |
| PTO | Please Talk Out
| Others |
| PTO | Please Turn Over
| Others |
| PTO | Please Turn the Page
| Others |
| PTO | Poetry Today Online
| Others |
| PTO | Pointer Table Overflow
| Others |
| PTO | Police Training Officer
| Others |
| PTO | Power Take Off
| Others |
| PTO | Power Take Offs
| Others |
| PTO | Power Take-Off
| Others |
| PTO | Power Test Operations
| Others |
| PTO | Power This Outlet
| Others |
| PTO | Powertrain Operations
| Others |
| PTO | Pre-Trial Order
| Others |
| PTO | Preliminary Technical Order
| Others |
| PTO | Prepare The Others
| Others |
| PTO | Presentation Text Object
| Others |
| PTO | Pretty Tractor Operator
| Others |
| PTO | Priority Target Organization
| Others |
| PTO | Prison Talk Online
| Others |
| PTO | Privilege Ticket Order
| Others |
| PTO | Process Time Out
| Others |
| PTO | Product Transfer Order
| Others |
| PTO | Professional Triathletes Organisation
| Others |
| PTO | Project Team and Organization
| Others |
| PTO | Propane Truck Operator
| Others |
| PTO | Public Telecommunication Operator
| Others |
| PTO | Public Telephone Operator
| Others |
| PTO | Public Transport Operator
| Others |
| Pto | Puerto
| Others |
| PTO | Pull Toyota Out
| Others |