| Acronym | Definition |
|---|
| OTC | Over The Counter (stocks) |
| OTC | Over The Counter (medications not requiring a prescription) |
| OTC | Offshore Technology Conference |
| OTC | Ozarks Technical Community College (Springfield, MO) |
| OTC | Oriental Trading Company |
| OTC | Open Text Corporation |
| OTC | Office of Technology Commercialization (various locations) |
| OTC | On The Contrary |
| OTC | Office des Transports du Canada (Canadian Transportation Agency) |
| OTC | Oxytetracycline (calcium complex) |
| OTC | Olympic Training Center |
| OTC | Ozone Transport Commission |
| OTC | One-Time Charge |
| OTC | Ornithine Transcarbamylase |
| OTC | Order To Cash |
| OTC | One Time Cost |
| OTC | Out of The Closet |
| OTC | Oregon Transportation Commission |
| OTC | Olivia Tremor Control (band) |
| OTC | Officer Training Corps |
| OTC | Overseas Telecommunications Commission |
| OTC | Operational Test Command (US Army; formerly Test and Experimentation Command) |
| OTC | Ornithine Carbamoyltransferase |
| OTC | Off the Chart (radio) |
| OTC | Office of Tobacco Control (Ireland) |
| OTC | Online Travel Company |
| OTC | Off The Clock |
| OTC | Office of Telecommunications |
| OTC | Oriental Timber Company |
| OTC | Once-Through Cooling (power plant treatment) |
| OTC | Old Timers Club |
| OTC | Order to Show Cause (civil law) |
| OTC | On the Chip |
| OTC | Ohio Turnpike Commission |
| OTC | Oshkosh Truck Corporation |
| OTC | Officer in Tactical Command |
| OTC | Other Than Collision (insurance term meaning comprehensive coverage) |
| OTC | Okefenokee Technical College |
| OTC | Owatonna Tool Company (Owatonna, MI) |
| OTC | Operating Telephone Company |
| OTC | Output Technology Corporation |
| OTC | Object Technology Center (Conference) |
| OTC | Olivos Tenis Club |
| OTC | Ogemaw Telephone Company (Michigan) |
| OTC | Office Technology Center |
| OTC | Ontario Teacher's Certificate (Canada) |
| OTC | On Tape Catalog |
| OTC | Open Technology Centre (UK) |
| OTC | Oregon Trail Council (Boy Scouts of America; Eugene, OR) |
| OTC | Organ Transplant Center |
| OTC | Out to Court |
| OTC | Orlando Tech Center (Florida) |
| OTC | Outsourcing Technology and Commercial (legal department) |
| OTC | Ottawa Tool Company |
| OTC | Operational Test Coordinator (US Navy) |
| OTC | Ottawa Torah Center |
| OTC | On Target Commission |
| OTC | Organic Toxic Compound |
| OTC | Ordnance Training Command |
| OTC | On-Scene Tactical Commander |
| OTC | Online Technology Consortium |
| OTC | Offsite Training Center |
| OTC | Ouaticha Technical College (Malvern, Arkansas) |
| OTC | Operational Training Capability |
| OTC | Outside the Classroom (est. 2000; Boston, MA) |
| OTC | Olney Theatre Center (Olney, MD) |
| OTC | Off the Chain |
| OTC | Other than Conscious Mind (psychology) |
| OTC | Opportunity to Correct |
| OTC | Office of Teacher Certification (various schools) |
| OTC | Office of Technical Cooperation (various locations) |
| OTC | One Thousand Children (Holocaust survival) |
| OTC | Out There Clothing |
| OTC | One Texas Center (Austin, TX) |
| OTC | One Team Conference |