| Acronym | Definition |
|---|
| MCSO | Multnomah County Sheriff's Office (Portland, Oregon) |
| MCSO | Marion County Sheriff’s Office |
| MCSO | Modulo Certified Security Officer (Brazil) |
| MCSO | Mecklenburg County Sheriff's Office (North Carolina) |
| MCSO | Mayes County Sheriffs Office (Oklahoma) |
| MCSO | Medical Center of Southeastern Oklahoma |
| MCSO | Montgomery County Sheriff's Department (Conroe, TX) |
| MCSO | Maricopa County Sheriffs Office (Arizona) |
| MCSO | Midcoast Symphony Orchestra (Brunswick, ME) |
| MCSO | Morris County Sheriff's Office (Morristown, New Jersey) |
| MCSO | Morrow County Sheriff's Office (Heppner, OR) |
| MCSO | Medical Coding Service Organization |
| MCSO | Musashino Civic Symphony Orchestra (Musashino, Japan) |
| MCSO | Maricopa County Sellers Organization (Phoenix, Arizona) |
| MCSO | Mission Control and Support Officer |
| MCSO | Methylene Chloride Soluble Organics |