RTA
- Central Puget Sound Regional Transit Authority
- Greater Cleveland Regional Transit Authority
- Greater Dayton Regional Transit Authority
- New Orleans Regional Transit Authority
- RTA (Niger)
- RTA (album)
- RTA 5 (Thailand)
- RTA Rapid Transit
- RTA TV
- RTA clade
- Race Team Alliance
- Radio Television Afghanistan
- Radio and Television Arts
- Radiodiffusion Télévision Algérienne
- Railway Tie Association
- Rapid thermal anneal
- Ready-to-assemble furniture
- Real-time analyzer
- Regional Transit Authority of Southeast Michigan
- Regional Transportation Agency of Central Maryland
- Regional Transportation Authority (Illinois)
- Regional trade agreement
- Rehabilitation Through the Arts
- Renal tubular acidosis
- Residential Tenancies Authority
- Restricted to Adults
- Retrolateral tibial apophysis
- Retrospective Think Aloud
- Rio Tinto Aluminium
- Rita (disambiguation)
- Riverside Transit Agency
- Road traffic accident
- Royal Thai Army
- San Luis Obispo Regional Transit Authority
- South Florida Regional Transportation Authority
- WeGo Star
- Ṛta