• TAM Airlines (TAM Linhas Aéreas), a Brazilian airline whose IATA code is JJ
• Brassiere cup size, JJ in the UK
• Johnson and Johnson, Johnson & Johnson a large US company owner of the domain JJ.com
• Triple J, an Australian radio station formerly known as Double Jay with the callsign 2JJ
• JJ (band), featuring Jan Johnston from the early 1990s (Columbia Records)
• JJ (magazine), a fashion magazine
• JJ (video game), a video game developed and published by Square Co., Ltd.
• Jay Jay, Tamil film starring R. Madhavan, Pooja and Amoga
• Jay Jay the Jet Plane, a CGI children's television cartoon fiction series
• Jason Jr. (ROV), a remotely operated vehicle (ROV) that belongs to the Woods Hole Oceanographic Institution (WHOI)
• Two or more judges, in court reporting (e.g. "Smith and Jones JJ"; singular J)

People

• JJ Lin, A Chinese-Singaporean singer-songwriter
• Lil' JJ, stand-up comedian
• J. J. Abrams, American film and television producer, writer, actor, composer and director
• J. J. Cale, an American songwriter and musician
• J. J. Johnson, jazz trombonist
• J. J. Redick, an NBA player, currently a member of the Orlando Magic
• JJ Osbun, American Entertainment Industry professional
• Jacinto João, a famous football player
• Joshua Jackson, Canadian-American actor
• Jan Jacob van Oosterzee (1817–1872) Dutch Theologian
• Jeff Jarrett, American professional wrestler
• Jelena Janković, Serbian tennis player
• Jermaine Jenas, English football player for Tottenham Hotspur
• Joe Johnson (basketball), an NBA player, currently a member of the Atlanta Hawks
• Judge Judy, television judge from the show with the same name
• J. Jonah Jameson, a Marvel Comics character
• Junaid Jamshed, Pakistani singer

See also

• J. J.