| HRO | Ham Radio Outlet 
| Others |
| HRO | Ham Rip Off
| Others |
| HRO | Harassment restraining order
| Others |
| HRO | Harassment Restraining Orders
| Others |
| HRO | Harrison, Arkansas USA
| Others |
| HRO | Harvard Radcliffe Orchestra
| Others |
| HRO | Harvard Radiation Oncology
| Others |
| HRO | Health Research Office
| Others |
| HRO | Heavy Recovery Orbiter
| Others |
| HRO | Hell Raising Outsourcing
| Others |
| HRO | Helluva Rush Order
| Others |
| HRO | High Reliability Organization
| Others |
| HRO | High Reliability Organizations
| Others |
| HRO | High Reliability Organizing
| Others |
| HRO | High Resolution Orthoimagery
| Others |
| HRO | High Resolution Orthophotography
| Others |
| HRO | High Resolution Oscilloscope
| Others |
| HRO | High Resolution Oscilloscopes
| Others |
| HRO | High Risk Offenders
| Others |
| HRO | Highly Reliable Organizing
| Others |
| HRO | Hillside Residential Open
| Others |
| HRO | Home Room One
| Others |
| HRO | House Research Organization
| Others |
| HRO | Human Resource Outsourcer
| Others |
| HRO | Human Resource Outsourcing
| Others |
| HRO | Human Resources Office
| Others |
| HRO | Human Resources Officer
| Others |
| HRO | Human Resources Operations
| Others |
| HRO | Human Resources Organization
| Others |
| HRO | Human Resources Outsourcers
| Others |
| HRO | Human Resources Outsourcing
| Others |
| HRO | Human Rights Ordinance
| Others |
| HRO | Humanitarian Relief Organizations
| Others |