OTA
- Djezzy GSM
- MSD Capital
- OTA bitmap
- Occupational therapy assistant
- Ochratoxin A
- Off the Air (TV series)
- Office of Technology Assessment
- Officers Training Academy
- Ohta (disambiguation)
- Oklahoma Turnpike Authority
- Online travel agency
- Ontario Temperance Act
- OpenTravel Alliance
- Operational transconductance amplifier
- Organic Trade Association
- Orthodontic Technicians Association
- Ota (disambiguation)
- Otakon
- Ottoman Turkish language
- Over-the-air (disambiguation)
- Over-the-air programming
- Oxford Text Archive
- Training camp (National Football League)