Fo or FO may refer to:
Arts and entertainment Fallout (video game), a 1997 video game Fo Fai, a character in the Battle Arena Toshinden video game series Folio (printing), a book size, the page number of books, or sheets with multiple printed pages Foreign Objects (band), a Pennsylvania music group FunOrb, a 2008 Java-based gaming website
Businesses and organisations Par Avion (airline) (IATA airline designator), airline of Tasmania, Australia Family office, an investing office controlled by a family Felix Airways (IATA airline designator), a regional airline of Yemen Football Outsiders, a website devoted to statistical analysis of the NFL Force Ouvrière, a French trade unions confederation Foreign Office, a department of the United Kingdom government, currently named Foreign, Commonwealth and Development Office Flybondi (IATA airline designator), airline of Argentina
Mathematics, science and technology Computing
FO (complexity), a complexity class .fo, the country code top level domain (ccTLD) for Faroe Islands Fiber optic XSL Formatting Objects (XSL-FO), a markup language
Other uses in mathematics, science, and technology Fan out (FO), number of loads at the output of a ring oscillator First-order logic, a system of mathematical logic Forsterite, magnesium-rich end-member in the olivine solid solution series Fourier number (Fo) in physics Fuel factor (Fo), used to check the accuracy of an emission measurement system Fuel oil, also called Furnace Oil FO, a subunit of F1FO type ATPase enzyme
Military or aeronautical roles Field officer, a senior army officer First Officer, or co-pilot on an airliner Flying officer, a Royal Air Force rank Forward Observer, a soldier who directs artillery fire
People Dario Fo (1926–2016), Italian playwright and Nobel laureate Fo Porter, a contestant on America's Next Top Model, Cycle 12 Fó or Fú (佛、仏), the Chinese translation of the term Buddha Franco-ontarien, referring to a French-speaking citizen of the (largely anglophone) Canadian province of Ontario, Canada
Places Faroe Islands, ISO 3166-1 country code, FO .fo, the country code top level domain (ccTLD) for Faroe Islands Faroese language (language code fo), a North Germanic language Fô Department of the Houet Province of Burkina Faso , the chief town in Fo Department Province of Forlì, Italy Fort Ord, California
Other uses Face Off (disambiguation) Faroese language (language code fo), a North Germanic language Foreign object (disambiguation) Front office, an area where visitors arrive and first encounter a staff at a place of business Fuck off (disambiguation), an English expletive, and various other meanings Furka Oberalp Railway, a Swiss railway Follow-on, a practice of making a team bat multiple innings in a row in cricket
See also Foe (disambiguation) Pho