PTA may refer to:

• Andalusia Technology Park (Spanish: Parque Tecnológico de Andalucía), a science park in Málaga, Spain
• Pakistan Telecommunication Authority, an agency in Pakistan responsible for communication networks.
• Parent–teacher association, an organization of parents, teachers, and staff at a school
• Passenger transport authority, a United Kingdom local government authority
• Public Transport Authority (Denmark)
• Public Transport Authority (Western Australia)

• 1,3,5-Triaza-7-phosphaadamantane, organic compound
• Percutaneous transluminal angioplasty, surgical procedure
• Peritonsillar abscess
• Persistent truncus arteriosus, congenital heart disease
• Pharmacy Technical Assistant
• Phosphate acetyltransferase, enzyme
• Phosphotungstic acid, acid catalyst and stain
• Physical Therapist Assistant
• Plasma thromboplastin antecedent, blood enzyme
• Plasma Transferred Arc, coating technology
• Post-traumatic amnesia, state of confusion following a traumatic brain injury
• Pulsar timing array, technique to detect gravitational waves
• Pure tone audiometry, hearing test
• Purified terephthalic acid, organic compound used to make polyester

• Paul Thomas Anderson, American filmmaker
• Planes, Trains and Automobiles, a 1987 American film by John Hughes
• Pohakuloa Training Area, a military training facility
• Point of total assumption, a contract term
• Preferential trading area, a type of trading bloc
• Pretoria, the administrative and de facto capital of South Africa
• Prevention of Terrorism Act, the name of several countries' Acts of Parliament
• Program test authority, after a construction permit but before a broadcast license
• Port Talbot Parkway railway station in Wales (station code)
• a possible mnemonic symbol for Peseta, the former Spanish currency