BIR or Bir may refer to:
Birmingham (/ˈbɜːrmɪŋəm/) is a city and metropolitan borough in the West Midlands, England. It is the largest and most populous British city outside London, with a population of 1,101,360 in 2014.
Birmingham (/ˈbɜːrmɪŋhæm/ BUR-ming-ham) is the most populous city in the U.S. state of Alabama and the county seat of Jefferson County.
Birth control, also known as contraception and fertility control, is a method or device used to prevent pregnancy.
Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds.
In probability theory, the birthday problem or birthday paradox concerns the probability that, in a set of
Birmingham Airport (IATA: BHX, ICAO: EGBB), formerly Birmingham International Airport and before that, Elmdon Airport is an international airport located 5.5 nautical miles (10.2 km; 6.3 mi) east southeast of Birmingham city centre, at Bickenhill in Solihull, England.