3R or three Rs may refer to:
- The three Rs, a widely used abbreviation for the basic elements of a primary school curriculum: reading, 'riting (writing), and 'rithmetic (arithmetic)
- The three Rs, a widely used abbreviation for the waste management hierarchy: reduce, reuse, and recycle
- The Three Rs (animals), principles for ethical use of animals in testing: replacement, reduction, refinement
- 3R (optical regenerator), an optical communications repeater that performs reamplification, reshaping, and retiming
- Intelsat 3R, a former communications satellite
- Yaesu VX-3R, an ultra-compact dual-band amateur radio transceiver
- British Rail Class 206, Southern Region designation 3R from 3-car Reading Line stock
- 3R (print size), a standard consumer print size for photographs
- The 3Rs of Junior Forest Wardens (a Canadian outdoor-education program for families): Responsibility to yourself, Responsibility to others, Responsibility to your community and the planet
- Return, Reclamation, Rehabilitation, rebel group in Central African Republic
- Relief, recovery, and reform, programs that were designed under these three categories during the New Deal
See also these
- RRR (disambiguation)
- R3 (disambiguation)