JJ (nickname)

As a nickname, JJ, J.J., or J. J. may refer to:

In arts and entertainment

 * Justo Justo or JJ (1941–2012), Filipino columnist and news presenter
 * J.J. Caucus, a character in the Doonesbury comic strip
 * J. J. Abrams (born 1966), American media director and producer
 * JJ Burnel (born 1952), Franco-English musician, singer-songwriter and producer
 * JJ Cale (1938–2013), American singer-songwriter, recording artist and influential guitar stylist
 * JJ Lin (born 1981), Singaporean mandopop singer-song writer, composer and actor
 * JJ Olatunji (born 1993), English YouTube personality and rapper also known as KSI
 * Jay-J (born 1969), American house music disc jockey
 * Jennifer Herrema or JJ, American singer and songwriter with the band Royal Trux
 * Junaid Jamshed or JJ (1964–2016), Pakistani recording artist and religious figure
 * Justin Quinn or JJ, British singer known for his vocals on songs by UK garage duo DJ Luck & MC Neat
 * Josie Totah or J. J. (born 2001), American actress
 * J.J., Band featuring English singer Jan Johnston
 * J.J. Villard, American animator and filmmaker, known for creating King Star King and JJ Villard's Fairy Tales.

In sports

 * JJ Lehto (born 1966), Finnish motorsport racing driver
 * J. J. Davis (born 1978), American baseball player
 * J. J. Koski (born 1996), American football player
 * J. J. Mann (born 1991), American basketball player
 * J. J. McCarthy (born 2003), American football player
 * JJ McKiernan (born 2002), English footballer
 * J. J. Moses (born 1979), American football player
 * J. J. Raterink (born 1981), American football player
 * JJ Redick (born 1984), American basketball player
 * J. J. Russell (born 1998), American football player
 * J. J. Syvrud (born 1977), American football player
 * J. J. Taylor (born 1998), American football player
 * J. J. Watt (born 1989), American football defensive end for the Houston Texans of the National Football League (NFL)
 * J. J. Williams (1948–2020), retired Welsh rugby union player
 * J. J. Yeley (born 1976), American NASCAR driver
 * Jermaine Jenas (born 1983) retired English professional footballer
 * Jimmie Johnson (born 1975), American Indycar driver

In other fields

 * Robert Jay (judge) (born 1959), noted in court reports as "Jay J."
 * Jonathan "JJ" Johnson, American businessman and politician from Utah
 * J. J. Thomson (1856–1940), English physicist
 * J. J. Valberg (1936), British-American philosopher
 * J.J. Webster (1898–1965), American politician
 * Jan Jambon (1960), Belgian politician