Books
* 999 (anthology), ''999'' (anthology) or ''999: Twenty-nine Original Tales of Horror and Suspense'', a 1999 anthology of short stories * ''Galaxy Express 999'', a manga and anime created by Leiji MatsumotoFilm and TV
* ''Triple 9'', a 2016 heist-thriller film * 999 (UK TV series), ''999'' (UK TV series), a British programme presented by Michael Buerk that aired on the BBC * 999 (Malaysian TV series), ''999'' (Malaysian TV series), a 2004 Malaysian crime reality television series * ''999: What's Your Emergency?'', a 2012 British factual programme following the emergency service * Triple Nine (TV series), ''Triple Nine'' (TV series), a Singaporean television series running from 1995 to 1999Music
* 999 (band), a London punk rock band active since the 1970s * 999 (album), ''999'' (album), a self-titled album by the band 999 * 999 (Selena Gomez and Camilo song) * 999 (Kent song), "999" (Kent song) * "999", a song from Keith Richards' album ''Main Offender'' (1992) * 999, a number often used by Juice WRLDTransportation
* Ducati 999, an Italian motorcycle * New York Central and Hudson River Railroad No. 999, the first steam locomotive in the United States to operate at faster than 100 mph * Ford 999, a pioneering 1902 racer named for the locomotiveOther uses
* 999 Zachia, an asteroid * 9–9–9 Plan, a tax plan proposed by 2012 Republican presidential candidate Herman Cain * 999 phone charging myth, an urban myth that calling the emergency services charges mobile phones * Nine (purity), an informal way of ranking purity; "three nines" would be 99.9% pure * "Three nines" as a level of high availability (99.9%) * Triple Nine Society, a society for people with IQs in the 99.9th percentile * Nine Hours, Nine Persons, Nine Doors, a 2009 video game developed by ChunsoftSee also
* 0.999... for proofs that 0.999... is equal to 1 {{Number disambiguation