Language
*Science, technology, and mathematics
Biology
* Troponin I, one of the three troponins * Haplogroup I (mtDNA), a human mitochondrial DNA (mtDNA) haplogroup * Haplogroup I (Y-DNA), a Y-chromosomal DNA (Y-DNA) haplogroup *Chemistry
*Computing
*i, a common generic index variable often used in program loops
* <i>, an HTML element for marking italic type
* .i, the common filename extension for a file that contains the output from a preprocessor
* i-, a prefix for Apple Inc., Apple products e.g. iMac, iPod, iPhone
* i-, an Internet-related prefixes#Use and meanings, Internet-related prefix used by Internet and electronic companies
Mathematics
* I, the Roman numeral for 1 * , imaginary unit, for which * or , identity matrix of indeterminate size (or of size ) * , unit interval, which contains all real numbers from 0 to 1 inclusive * , an index variable, e. g. in a matrix (mathematics), matrix or for summation * , the regularized incomplete beta function (of a variable and parameters ) * , the unit vector along the ''x''-axis in Cartesian coordinatesPhysics and astronomy
* , , electric current * , isospin * , luminous intensity * , moment of inertia * , orbital inclination * I (Roman number one), in the Yerkes spectral classification scheme, the symbol for supergiantsTelecommunication
* I band (NATO), the range of radio frequencies from 8 GHz to 10 GHz in the electromagnetic spectrum * I, the ITU prefix allocated to Italy in radio communication * I, in QAM modulation schemes, the in-phase communications channelOther uses in technology
* i, a suffix unit for video resolution (vertical Interlaced lines), as in 480i or 1080i * ''I'', in the YIQ colorspace commonly used with the NTSC television encoding scheme, the color-difference channel which is in-phase with the subcarrierArts and media
Music
* I (band), a Norwegian heavy metal band * I, a diatonic function in tonal music theoryAlbums
* i (A.R. Kane album), ''i'' (A.R. Kane album), 1989 * I (Ben Lester album), ''I'' (Ben Lester album), 2019 * I (Cilvaringz album), ''I'' (Cilvaringz album), 2007 * I (Cursed album), ''I'' (Cursed album), 2003 * I (Die Krupps album), ''I'' (Die Krupps album), 1992 * I (Felix Jaehn album), ''I'' (Felix Jaehn album), 2018 * I (Ikimono-gakari album), ''I'' (Ikimono-gakari album), 2013 * I (Jaejoong EP), ''I'' (Jaejoong EP), 2013 * I (JonnyX and the Groadies album), ''I'' (JonnyX and the Groadies album), 2005 * I (Juju album), ''I'' (Juju album), 2018 * I (Kingston Wall album), ''I'' (Kingston Wall album), 1992 * I (Kurt Nilsen album), ''I'' (Kurt Nilsen album), 2003 * i (The Magnetic Fields album), ''i'' (The Magnetic Fields album), 2004 * I (Meshuggah EP), ''I'' (Meshuggah EP), 2004 * i (Misako Odani album), ''i'' (Misako Odani album), 1997 * I (Nightingale album), ''I'' (Nightingale album), 2000 * I (Petbrick album), ''I'' (Petbrick album), 2019 * I (Sahg album), ''I'' (Sahg album), 2006 * I (Taeyeon EP), ''I'' (Taeyeon EP), 2015 * I (Xerath album), ''I'' (Xerath album), 2009 * I (soundtrack), ''I'' (soundtrack), by A. R. Rahman from the eponymous 2015 filmSongs
* I (Kendrick Lamar song), "i" (Kendrick Lamar song), a 2014 song by Kendrick Lamar from his album ''To Pimp a Butterfly'' * I (Lil Skies song), "i" (Lil Skies song), a song 2019 by Lil Skies from his debut album ''Shelby'' * I (Taproot song), "I" (Taproot song), a 2001 song by band Taproot from their album ''Gift'' * "I (Who Have Nothing)", a 1966 Ben. E. King song also recorded by Tom Jones, who used the title for one of his albums * "I", a 2003 song on ''Weather Systems (Andrew Bird album), Weather Systems'', an album by Andrew Bird * "I", a 1992 song on ''Selected Ambient Works 85–92'', an album by Aphex Twin * "I", a 1992 song on ''Dehumanizer'', an album by Black Sabbath * "I", a 1997 song on ''Coal Chamber (album), Coal Chamber'', an album by Coal Chamber * "I", a 1967 song on ''Underground (The Electric Prunes album), Underground'', an album by The Electric Prunes * "I", a 2012 song on ''Muse (Jolin Tsai album), Muse'', an album by Jolin Tsai * "I", a 1981 song on ''Music from "The Elder"'', an album by Kiss * "I", a 1994 song on ''Made in USA (Pizzicato Five album), Made in USA'', an album by Pizzicato Five * "I", a 1999 song on ''Eternal (Samael album), Eternal'', an album by Samael * "I", a 2003 song on ''Winter Story (Shinhwa album), Winter Story'', an album by Shinhwa * "I", a 2015 song on ''I (Taeyeon EP), I'', an EP by Taeyeon * "I", a 2016 song by Rezz * "I", a 2019 song by Hey! Say! JUMPOther media
* I (2015 film), ''I'' (2015 film), an Indian Tamil-language film * I (2016 film), ''I'' (2016 film), an Iranian film * i (TV network), the former name of ION Television * I (newspaper), ''i'' (newspaper), a British newspaper based in London * I (Portuguese newspaper), ''i'' (Portuguese newspaper), a Portuguese newspaper based in Lisbon * I, a character in the comic book series ''Adventure into Fear'' * ''"I" Is for Innocent'', the ninth novel in Sue Grafton's "Alphabet mystery" series, published in 1992 * ''I, a Man'', a 1967 Andy Warhol filmMythology
* Goddess I, a Mayan deity * Hou-i, or I, a heroic archer and hunter in Chinese mythologyVehicles
* Italy (I), in the list of international vehicle registration codes * Italy (aircraft registration prefix) * Mitsubishi i, a Japanese kei carOther uses
* i, an international symbol for visitor or tourist information; see ISO 7001 * Nintendo DSi, the third model in the Nintendo DS line, released in 2008 * Nintendo DSi#Larger model, Nintendo DSi XL, the larger version of the DSi, released in 2009 * I, an alternative romanization of Lee (Korean surname) * I-Foundation, a charity in charge of state-funded Hindu faith schools in the United Kingdom * Interest rate (i), in economics * Investment (I), in economics * List of military time zones#I, India, the military time zone code for UTC+09:00See also
* 1 (disambiguation) * l (disambiguation) * Eye (disambiguation) * Self * {{Disambiguation