Sir (disambiguation)

Sir is a respectful form of address for a man, and a formal title used in the United Kingdom for knights and baronets.

Sir, SIR or SiR may also refer to:

Iran

 * Sir, Iran, a city in Fars Province
 * Sir, Razavi Khorasan, a village in Razavi Khorasan Province
 * Sir, West Azerbaijan, a village in West Azerbaijan Province

West Bank

 * Sir, Jenin, a Palestinian village in Jenin district
 * Sir, Tulkarm, a Palestinian village in Tulkarm district

Others

 * Sir Creek, on the border between India and Pakistan

People

 * Sir (singer), American singer, songwriter, record producer
 * Jaroslav Šír (born 1923), Czechoslovak former skier
 * József Sir (1912–1996), Hungarian sprinter
 * Sedat Sir (born 1975), Turkish-Australian former Australian Rules footballer

Entertainment

 * Sir (1993 film), a Bollywood film
 * Sir (A Series of Unfortunate Events), a fictional character in A Series of Unfortunate Events
 * Sir (album), by Fischerspooner
 * Sir (2018 film), an Indian Hindi-language romantic drama film
 * "Sir", a song by Nicki Minaj from Queen

Organizations

 * Sigma Iota Rho, a collegiate honour society for international studies
 * Society of Interventional Radiology, an American organization of health professionals
 * Sons In Retirement (SIR), a fraternal organization of retired men

Mathematics and statistics

 * Sequential Importance Resampling, in mathematics, a particle filtering algorithm
 * Signal-to-interference ratio, in telecommunication, the ratio of useful signal versus co-channel interference received
 * Short interest ratio, a metric signalling prevailing investors' sentiment
 * SIR model, a compartmental model of the progress of an epidemic

Other uses

 * SIR proteins (silent information regulator), in molecular biology
 * Saskatchewan International Raceway, a Saskatoon drag strip
 * Security Industry Registry, a corporate service provided by the New South Wales Police Force
 * Siantar railway station, Pematang Siantar, Indonesia (station code: SIR)
 * Singapore Infantry Regiment, the main formation of the Singapore Army
 * Sion Airport (IATA code: SIR), the airport in Sion, Switzerland
 * South Indian Railway, an early Indian railway company
 * Staten Island Railway, rapid transit line in the borough of Staten Island, New York, United States
 * Statutory Invention Registration, publication of an invention by the United States Patent and Trademark Office
 * Surrey Iron Railway, a horse-drawn plateway that linked the former Surrey towns of Wandsworth and Croydon
 * Serial Infrared, a category of Infrared Data Association
 * Secondary Image Registration, a type of passive autofocus
 * Supplemental Inflatable Restraint or airbag, a vehicle safety device

Other uses

 * Sır Dam, on the Ceyhan River in Turkey
 * Sirene (Sir in Serbian), a type of cheese