R², the two-dimensional vector space of real numbers in mathematics

R2-D2, a character from Star Wars films and books

BBC Radio 2, a British radio station

DVD region code 2

any astromech droid in the Star Wars fictional universe

R2 signalling, a family of telephony protocols for line and register signalling

<math>R^2</math>, a symbol for the coefficient of determination of a linear regression

Haplogroup R2 (Y-DNA)

R2 (SEPTA), a regional rail line in Philadelphia, Pennsylvania

Orenburg Airlines by IATA code

R-2 rocket

Patricio Rey y sus Redonditos de Ricota or R2, an Argentine rock band

Subaru R2, a vehicle

TSRTWO or R2, a super computer in Vancouver, BC, Canada