RR or rr may refer to:
RR Donnelley is a Fortune 500 integrated communications company that provides marketing and business communications, commercial printing, and related services.
Ribonucleoside-diphosphate reductase subunit M2 B is an enzyme that in humans is encoded by the RRM2B gene.
RRS Discovery was the last traditional wooden three-masted ship to be built in Britain. Designed for Antarctic research, it was launched as a Royal Research Ship (RRS) in 1901. Its first mission was the British National Antarctic Expedition, carrying Robert Falcon Scott and Ernest Shackleton on their first, successful journey to the Antarctic, known as the Discovery Expedition.
RRDtool (round-robin database tool) aims to handle time series data such as network bandwidth, temperatures or CPU load.
RRS Sir David Attenborough is a research vessel owned by the Natural Environment Research Council, to be operated by the British Antarctic Survey for the purposes of both research and logistic support.
RR Auction is an auction house headquartered in Boston’s North End with a production office based in Amherst, New Hampshire.
RRT Global is an international company that specializes in the development of technologies for oil refining process.
RR Lyrae is a variable star in the Lyra constellation, located near the border with the neighboring constellation of Cygnus.