Re

Re or RE may refer to:

Arts, media and entertainment

...Re (film), a 2016 Indian Kannada-language film
Realencyclopädie der classischen Altertumswissenschaft, a German encyclopedia of classical scholarship
Resident Evil, a horror game franchise

Re, the second syllable of the scale in solfège
- D (musical note) or Re, the second note of the musical scale in fixed do solfège
Re: (band), a musical duo based in Canada and the US

re (interjection), in Greek
Re (kana) (れ and レ), Japanese syllables
In re, Latin for 'in the matter of...'
- RE: and Re:, a standard email subject line prefix

Renew Europe, a political group in the European Parliament
Renovación Española, a former Spanish monarchist political party
Royal Engineers, a part of the British Army
Royal Society of Painter-Printmakers, whose fellows may use the Post-nominal letters RE
Stobart Air (former IATA code: RE), a former Irish regional airline

Re, Norway, a former municipality in Vestfold county
Re, Vestland, a village in Gloppen municipality, Vestland county, Norway
Re, Piedmont, an Italian municipality
Île de Ré, an island off the west coast of France
- Le Bois-Plage-en-Ré, a commune on that island
Re di Anfo, a torrent (seasonal stream) in Italy
Re di Gianico, Re di Niardo, Re di Sellero, and Re di Tredenus, torrents in the Val Camonica, Lombardy, Italy
Réunion (ISO 3166-1 code), a French overseas department and island in the Indian Ocean

Effective reproduction number, in epidemiology
Relative effectiveness or RE factor, of an explosive's demolition power
Reynolds number ( $Re$ ), a dimensionless quantity in fluid mechanics used to help predict flow patterns
Rhenium (symbol Re), a chemical element
Reference pressure (Re), as sound pressure level
Reference pressure (Re), in underwater acoustics

RE (complexity) (recursively enumerable), a complexity class of decision problems
- Recursively enumerable (r.e.), in computability theory
Regular expression, a sequence of characters to match text against a specified pattern
Re function, in mathematics, where Re(z) denotes the real part of a complex number z