H.264 block diagram with quality score.jpg

H is the eighth letter of the Latin alphabet.

H may also refer to:

Musical symbols

* H number, Harry Halbreich reference mechanism for music by Honegger and Martinů
* H, B (musical note)
* H, B major

People

* H. (noble) (died after 1279), an unidentified nobleman in the Kingdom of Hungary who served as master of the horse
* H. (1900–1995), British activist and economist Edgar Hardcastle
* H (born 1957), British guitarist Adrian Smith
* H (born 1976), British singer Ian Watkins (Steps)
* h (born 1959), British vocalist Steve Hogarth
* H (born 1981/82), one of the attackers in the Sydney gang rapes
* H. (born 1925), girl who gave birth to a child when she was six years old
*H Waldman (born 1972), American-Israeli basketball player

Science and mathematics

* h, hour
* h, hecto-, the SI prefix for hundred or 10²

Biology

* Haplogroup H
** Haplogroup H (mtDNA), human mitochondrial DNA
** Haplogroup H (Y-DNA), human Y-chromosome DNA
* ATC code H ''Systemic hormonal preparations, excluding sex hormones and insulins'', a section of the Anatomical Therapeutic Chemical Classification System
* Fay and Wu's H, a statistical test used in DNA analysis

Chemistry

* Hydrogen, symbol H, a chemical element
* H, code for a formulation of sulfur mustard

Computer science

* Language H, procedural programming language
* or , suffixed to denote Hexadecimal#Representing hexadecimal, hexadecimal in Intel-derived assembly languages
* .h, the filename extension for the C Include directive#C/C++, include directive called header

Linguistics

* , the International Phonetic Alphabet symbol for a voiceless glottal fricative sound
* H or high, the high-prestige register in a diglossia

Mathematics

* H, the upper half-plane of the complex numbers
* , the Heaviside step function
* h, impulse response in LTI system theory
* H, system function, system response, or transfer function in LTI system theory

Physics and cosmology

Constants

* h, Planck constant
* H, Hubble constant
* h, dimensionless Hubble constant

Measures

* H, absolute magnitude in the context of the Solar system
* H (as in ), magnitude of enthalpy
* h, Convection (heat transfer), convective heat transfer coefficient
* H, magnetic field intensity

Other uses in physics

* H, symbol for the Henry (unit), the SI derived unit of inductance
* H⁰, the symbol of the Higgs boson

Planets

* H, distortion of symbol for Uranus
* h, distortion of symbol for Saturn

Other uses in science

* h-index, an author-level metric of the productivity and citation impact of the publications of a scientist or scholar

Arts and media

Film and TV

* H (1990 film), ''H'' (1990 film), a 1990 Canadian film
* H (2002 film), ''H'' (2002 film), a 2002 Korean film
* H. (2014 film), ''H.'' (2014 film), a 2014 American film by Rania Attieh and Daniel Garcia
* H (TV series), ''H'' (TV series), a 1998-2002 French TV series
* H, the production code for the 1964 ''Doctor Who'' serial ''The Reign of Terror (Doctor Who), The Reign of Terror''
* H, a codename used to refer to an anonymous individual in the police procedural drama ''Line of Duty''
* "H", the fifth episode of the sixth series of ''List of Taskmaster episodes#Series 6 (2018), Taskmaster'' that aired in 2018

Music

*''h'', a 1990 compilation album by Hitomi (singer)
*''H'', a 1980 album by Bob James (musician)
* H (Ayumi Hamasaki EP), ''H'' (Ayumi Hamasaki EP), 2002
* H (Lee Hae-ri EP), ''H'' (Lee Hae-ri EP), 2017
* H. (song), "H." (song), a song by Tool on their 1996 ''Ænima'' album

Other media

*H (magazine), ''H'' (magazine)
* Revista H, a monthly Mexican men's magazine
* ''"H" Is for Homicide'', the eighth novel in Sue Grafton's "Alphabet mystery" series, published in 1991

Other uses

* Heroin
* Н, a letter of the Cyrillic alphabet analogous to N
* Һ, letter Shha of the Cyrillic alphabet
* Trains:
** H (S-train), a train service in Metropolitan Copenhagen
** H, Rockaway Park Shuttle subway service in New York
** Line H (Buenos Aires Underground), Line H of the Buenos Aires Subte
* H, a Hitachi, Ltd. mobile phone
* H, Hentai#H or "Etchi", sexual content or activity, associated with Japanese "Hentai"
* Hurricane tie, used in construction
* Conservative Party of Norway (''Høyre'')
* The military designation for helicopters, such as the UH-60 Blackhawk and AH-64 Apache
* H, a symbol for a heliport
* H, the international license plate code of Hungary
* Hit (baseball)
* Farmall H, a tractor produced by International Harvester from 1939 to 1953
* Hotel, the List of military time zones#H, military time zone code for UTC+08:00

See also

* Aitch (disambiguation)
* H class (disambiguation)
* H band (disambiguation)
* ^H, characters representing the backspace control code
* հ, an Armenian letter
* ㅐ, a Korean letter
* Ħ (H with stroke), a Maltese letter
* Н, a Cyrillic capital letter "En"
* Η, Greek capital letter eta

{{disambiguation
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la:H#Abbreviationes
hu:H#Jelentései
ja:H#Hの意味
nn:H#Bruk
simple:H#Meanings for H
fi:H#H-kirjaimen merkityksiä
sv:H#Betydelser