RK may refer to:
Science and technology
- Radial keratotomy, a surgical procedure on the eye
- Rhodopsin kinase, an enzyme
- r/K selection theory, in biology, relating to the trade-off between quantity and quality of offspring
- Runge–Kutta methods, in numerical analysis
Airlines
- Royal Khmer Airlines (former IATA code: RK), ceased operations 2007
- R Airlines (former IATA code: RK), ceased operations 2018
- Ryanair UK (IATA code: RK), UK based subsidiary airline of Ryanair
Other uses
- Raising Kaine, a defunct Virginia political blog
- Reichskommissariat, a historical Nazi territorial division
- Rangkasbitung railway station, station code RK
- Ridwan Kamil, former governor of West Java province since 2018-2023
See also
- RK (RynnäkköKivääri), Finnish assault rifles; for example RK 62
- Republic of Korea (ROK)
- Republic of Kazakhstan