OHS may refer to:
- Obesity hypoventilation syndrome
- Occipital horn syndrome
- Occupational Health and Safety
- Ochsner Health System
- Office of Homeland Security, Office of the Executive Branch of the United States, precursor to the Department of Homeland Security
- Oh's, a brand of cereals
- Ohio Historical Society
- Oklahoma Historical Society
- Ontario Handweavers & Spinners
- Oracle HTTP Server
- Oregon Historical Society
- Organ Historical Society, in Richmond, Virginia, United States
- Ottawa Humane Society
- Oxford Harmonic Society
Read more about OHS: High Schools