RCT
- JPEG 2000
- Jean-Philippe Rameau
- RC Toulonnais
- Radiochemotherapy
- Randomized controlled trial
- Ranipokhari Corner Team
- Rational choice theory
- Regents Competency Test
- Regimental combat team
- Register of Clinical Technologists
- Rehabilitation and Research Centre for Torture Victims
- Relational-cultural therapy
- Reverse cholesterol transport
- Reverse conducting thyristor
- Rhondda Cynon Taf
- Ritchey–Chrétien telescope
- RollerCoaster Tycoon
- RollerCoaster Tycoon (video game)
- Root canal treatment
- Rose City Transit
- Royal Corps of Transport
- Rubber Chemistry and Technology
- Rural Community Transportation
- Taxation in the Republic of Ireland