R2

R2 may refer to:
* DVD region code 2
* $R^2$, a symbol for the coefficient of determination of a linear regression
* R², the two-dimensional vector space of real numbers in mathematics
* R2 (SEPTA), a regional rail line in Philadelphia, Pennsylvania
* R2 signalling, a family of telephony protocols for line and register signalling
* R-2 rocket
* , a risk phrase in chemistry
* R2-D2, a character from "Star Wars" films and books
** any astromech droid in the "Star Wars" fictional universe
* Haplogroup R2 (Y-DNA)
* Motorroad R2 (Slovakia)
* Subaru R2, a vehicle
* USS R-2 (SS-79), a 1918 R-class coastal and harbor defense submarine of the United States Navy
* BBC Radio 2, a British radio station
* Orenburg Airlines by IATA code
* Patricio Rey y sus Redonditos de Ricota or R2, an Argentine rock band
* Windows Server 2003 R2
* an abbreviation to the video game Resistance 2
* "", a 2008 anime series
* , an online game