// Workers AI · dad joke modeWhy was J confused? It was disjointed.

J, or j, is the tenth letter of the English alphabet.

J may also refer to:

Alphabet characters

• J, Cyrillic letter Je
• ⟨j⟩, the voiced palatal approximant in the International Phonetic Alphabet
• ʲ, the symbol for palatalization in the IPA

Arts and entertaiment

Fictional characters

• Agent J, in the Men in Black films
• J, a Bobobo-bo Bo-bobo character
• Serial Designation "J", in 2021–2024 web series Murder Drones
• J, the narrator of Jerome K. Jerome's novel Three Men in a Boat

Film and television

• Canal J, a French children's television channel
• J, the production code for the 1964 Doctor Who serial Planet of Giants

Literature

• J (novel), by Howard Jacobson, 2014
• "J", a 1963 short story by Kenzaburō Ōe
• J. The Jewish News of Northern California, an American newspaper

Music

For musicians known as "J", see § People.

• J Records, a record label
• J (Jaehyun album), 2024
• "J", a song by Reggie and the Full Effect from the 2008 album Last Stop: Crappy Town
• "J", a song by Mindless Self Indulgence from the 2000 album Frankenstein Girls Will Seem Strangely Sexy

People

• J (musician) (Jun Onose, born 1970), Japanese rock musician
• J (South Korean singer) (Chung Jae-young, born 1977)
• J, pen name of Cornelia von Levetzow (1836–1921), Danish novelist
• J, a member of the K-pop group STAYC
• J., stage name of American White Zombie guitarist Jay Yuenger (fl. from 1982)
• J., stage name of German musician Jaye Muller (born 1967)
• J., a pseudonym of Jezper Söderlund (born 1980), Swedish record producer and electronic music artist
• J Dilla (James Dewitt Yancey, 1974–2006), American rapper
• J Mascis (Joseph Donald Mascis Jr, born 1965), American singer and guitarist of Dinosaur Jr.
• J Mays (born 1954), American industrial designer

Science and technology

Astronomy

• J, a provisional designation in astronomy for objects discovered between May 1 and 15 of a year

Computing

• J (programming language)
• J# programming language for the Microsoft .NET Framework
• J operator, a programming construct
• J (operating system), for ICL's System 4 series of computers

Genetics and medicine

• Haplogroup J (mtDNA)
• Haplogroup J (Y-DNA)
• ATC code J Antiinfectives for systemic use, a section of the Anatomical Therapeutic Chemical Classification System

Mathematics

• J, symbol used to denote the Bessel function
• j or i, symbol for the imaginary unit (${\sqrt {-1}}$)
• j, a hyperbolic unit in a split-complex numbers
• j, a basis vector of a quaternion
• j, an index variable in a matrix
• j-invariant, a modular function
• $J$, symbol for second moment of area for an axis perpendicular to the plane

Physics and chemistry

• J, symbol for Joule, the SI unit of energy
• ${\mathsf {J}}$, the dimension symbol for luminous intensity
• j →, symbol for current density
• J/psi meson, a subatomic particle
• J-coupling, indirect dipole-dipole coupling between two nuclear spins
• J, for Jod, chemical element iodine in German and early periodic tables
• J band (disambiguation), several uses

Transportation

Rail

• J (Los Angeles Railway), in the United States
• J Line (Los Angeles Metro), in the United States
• J/Z (New York City Subway service), in the United States
• J Church, an urban rail transit line of the Muni Metro system in San Francisco, California, United States
• NZR J class (disambiguation), two classes of steam locomotive in New Zealand
• Line J on the Transilien Paris-Saint-Lazare in France
• , the Bantan Line in Asago City, Hyōgo Prefecture, Japan
• "The J", the Elgin, Joliet and Eastern Railway, in Indiana, United States

Road

• Saviem J, and Renault J, a range of medium-duty trucks
• Guy Big J, a 1964–1978 range of trucks by Guy Motors of England
• Lamborghini Aventador J, a 2012 soecial edition sports car

Other uses

• J, slang for joint (cannabis)
• J, slang for a jump shot in basketball
• 1,3-Benzodioxolylbutanamine, or J, a psychedelic drug
• J, the international vehicle registration code for Japan
• J, the Postal code in Canada for the western and northern Quebec
• J, German Euro coin mint mark for Hamburg
• Jahwist (J), a widely recognized source of the Pentateuch
• J, abbreviated title of a High Court judge in England and Wales
• J, or Juliet, sometimes used a military time zone for local time

See also

• Jay (disambiguation)
• Jay Jay (disambiguation)
• Jay-Z (Shawn Corey Carter, born 1969), American rapper
• JJJ (disambiguation)
• J/22, J/24 and J/80 sailboat classes
• Kamen Rider J, a Japanese movie
• "J" Is for Judgment, a 1993 Sue Grafton "Alphabet mystery" series novel