OB
OB or Ob may refer to:

Arts and entertainment
Sam "O.B." O'Brien, a fictional character in the British soap opera Hollyoaks
Orphan Black, a Canadian science fiction television show
Ob, a fictional currency in The Great Explosion

Businesses and organizations
Odense Boldklub, a Danish football club
Oriental Brewery, a South Korean brewery, which produces the OB lagers
Outward Bound, an international outdoor education organization
Astrakhan Airlines (IATA code) (defunct)
Boliviana de Aviación (IATA code)

People
Ed O'Bradovich, an American former professional football player, known as "OB"
Old Badmintonians, former pupils of Badminton School, Bristol, England
Old Bedfordians, former pupils of Bedford School, England
Old Bristolians, former pupils of Bristol Grammar School, England

Places
Ob (river), a river in West Siberia, Russia
Ob Sea, an artificial lake on the river Ob
Ob, Russia, a town in Novosibirsk Oblast, Russia
Ob, Germany, in Bidingen, Bavaria, Germany
Gulf of Ob, a bay of the Arctic Ocean in Northern Russia
Oak Bluffs, Massachusetts
Ocean Beach, San Diego, a neighborhood of San Diego, California, United States

Science and technology
OB star, in astronomy, a hot, massive star of spectral types O or B
Object Manager (Windows), a Windows NT subsystem
Obstetrics, a medical specialty dealing with childbirth, often used in "obstetrics and gynaecology" (abbreviated OB/GYN)
Oligonucleotide/Oligosaccharide DNA-Binding-fold domain
Organizational behavior, an academic field
Outside broadcasting, a television broadcasting from a mobile television studio, such as a van
Obliterative bronchiolitis, a disease that results in obstruction of the smallest airways of the lungs due to inflammation

Other uses
ob., died, from Latin obitus. Also ob. inf. (died in infancy), ob. inf. Set. (died as minor), ob. inn. (died a spinster), ob. juv. (died in childhood)
o.b. (brand), a brand of feminine hygiene products
Halfpenny (British pre-decimal coin), from "ob", archaic abbreviation (see, e.g., Shakespeare's Henry IV, Part One, II.iv.539)
Order of Burma
"Over-the-counter bulletin board", in stock listings
Organizational behavior
Order of battle
"Out of bounds", an area outside the course play area, in golf

See also
Obese Records, a former Australian record label, founded as a record store in Melbourne called O.B.'s
Obi (disambiguation)
Obie (disambiguation)
OOB (disambiguation)