SN

SN can mean

* Brussels Airlines IATA code
* Sabena, the airline company that was the precursor of Brussels Airlines
* Snow METAR Code
* Standards Norway (Standard Norge) - the peak standards body of Norway
* Stronnictwo Narodowe, Polish political party
* Sodium nitrite
* Supernova
* Sigma Nu fraternity
* Surname, an attribute of the LDAP protocol family
* Sutta Nipata, a popular book of the Buddhist Pāli canon's Khuddaka Nikaya
* One of Jacobi's elliptic functions
* SN postcode area, the UK postcode district containing Swindon and much of North Wiltshire

Sn or sn can mean:

* Tin, the metallic element (from Latin for Tin: "stannum")
* sine nomine, Latin for "without a name", used in bibliographical catalogs to indicate publisher, etc is unknown
* Shona language (ISO 639 alpha-2, sn)
* S_"n", a symmetric group
* .sn, the ccTLD of Senegal
* sn, screenname used in instant messaging