OHS

• Oakland High School (California)
• Oakmont High School
• Oakton High School
• Obesity hypoventilation syndrome
• Occipital horn syndrome
• Occupational safety and health
• Oceanside High School
• Ochsner Health System
• Odessa High School
• Office of Homeland Security
• Ogden High School (Utah)
• Ohio Historical Society
• Ohs (Cereal brand)
• Oklahoma Historical Society
• Olympian High School
• Olympic High School (Charlotte, North Carolina)
• Olympic High School (disambiguation)
• Onehunga High School
• Ontario Handweavers & Spinners
• Opelika High School
• Oracle HTTP Server
• Orange High School (disambiguation)
• Oregon Historical Society
• Orem High School
• Organ Historical Society
• Oriel High School
• Orion High School
• Oromocto High School
• Osborne High School (Georgia)
• Ottawa Humane Society
• Ottawa Senior High School
• Ottumwa High School
• Oxford Harmonic Society
• Oxford High School (Oxford)
• Society for Occupational Health Psychology
• Stanford University Online High School