SR

SR, in each context, may stand for:

;Geography
* Saudi riyal, the currency of Saudi Arabia.
* Slovak Republic
* Socialist Republic, as in "SR Serbia", "SR Croatia", etc.
* Suriname (ISO 3166-1 alpha-2 country code)
* San Rafael

;Organisations
* Socialist-Revolutionary, as in Socialist-Revolutionary Party.
* Sørvágs Róðrarfelag, a Faroese rowing association.
* Saarländischer Rundfunk, a German regional public broadcasting company.
* Sveriges Radio, Sweden's national publicly-funded radio broadcasting company.

;Science
* Strontium, Sr, a chemical element of atomic number 38
* sr stands for steradian, the SI unit of solid angle.
* "Sedimentation rate", shorter form of the medical term Erythrocyte Sedimentation rate
* Sarcoplasmic reticulum, a structure found within muscle cells
* Single-reduction, a type of steam turbine
* Sinus rhythm, the pattern made by a healthy heart on an electrocardiogram
* Special relativity, a theory of space and time created by physicist Albert Einstein
* Strouhal number, a number used to describe oscillating flow mechanisms
* Sustained release formulation of a medicine, e.g. Wellbutrin SR
* Synchrotron radiation, electromagnetic radiation from charged particles moving in magnetic fields
* Systematic review standardized review

;Electronics and Technology
* SR "flip-flop" circuit, an electronic logic device
* SR programming language, a concurrent computer programming language
* Shift register, a group of processor registers set up in a linear fashion
* Selective repeat, a type of Automatic Repeat-reQuest Protocol.
* Speech recognition, the process of converting speech to text.
* Sound reinforcement, a high-power audio system.
* Steam reforming

;Transport
* Silk Road, a historically-significant interconnected series of caravan and ocean vessel trading routes across south-east Asia
* Southern Railway (UK)
* Southern Railway (US)
* State Road / State Route, a road designation system in the U.S. state system
* Swissair (IATA code)
* Nissan SR engine

;Culture
* Steel Reserve, an alcoholic beverage.
* Straylight Run, an American alternative/indie band.
* "School Rumble", an anime and manga series.
* "Shadowrun", a cyberpunk fantasy roleplaying game.
* "Simply Red", a pop/rock band
* "Skarloey Railway", a fictional railway in both "The Railway Series" and "Thomas the Tank Engine and Friends" by W.V. Awdry
* "Sonic Riders" or "Sonic R", both racing video games from the Sonic the Hedgehog series
* "Sonic Rush", a video game
* "Steve Rothery", the guitarist of Marillion
* "Superman Returns", a 2006 film based on the iconic superhero
* "Saints Row", a 2006 videogame.
* "Speed Racer", an anime from the 60s, as well as a "2007 feature film";Other
*Space Ranger, member of the Universe Protection Unit, protects the galaxy from the threat of invasion from the Evil Emperor Zurg, sworn enemy of the Galactic Alliance.
* Spelling reform, demonstrably different from simplified spelling (particularly in the case of Hebrew).
* scoville rating, a measure of the "hotness" of a chili pepper
* Seaman Recruit, the lowest enlisted rank in the U.S. Navy and Coast Guard
* Suburban Rhythm, a ska/punk band

r.

Sr. may stand for:
* Senior, added after a father's name when his son (suffixed "Jr.") has the same name.
* Sister, a nun's formal title.

sr

sr may stand for:
* Serbian language (ISO 639 alpha-2)
* Steradian, a unit of solid angle.