JJ or jj may refer to:
JJ Lin (traditional Chinese: 林俊傑; simplified Chinese: 林俊杰; pinyin: Lín Jùn Jié) is a Singaporean singer, songwriter, record producer and actor based in Taiwan.
Juan José Rendón Delgado (born 1964 in Caracas, Venezuela), known professionally as JJ Rendon, is a non-progressive Latin American political consultant, psychologist and political activist.
JJCC (pronounced J-J-C-C, Hangul: 제이제이씨씨) is a six-member South Korean hip-hop boy group formed under the management of Jackie Chan Group Korea.
Jyrki Juhani Järvilehto (Finnish pronunciation: [ˈjyrki ˈjærvilehto]; born 31 January 1966 in Espoo), better known as "JJ Lehto", is a Finnish racing driver.
JJK Jyväskylä (JJK) is a Finnish football club, based in Jyväskylä. It currently plays in the Finnish second highest league Ykkönen.
John Joseph Feild (born 1978), known professionally as JJ Feild, is a British-American actor.
JJB Sports plc (stylized as JJb sports) was a British sports retailer. On 24 September 2012, shares in JJB Sports were suspended, and the firm called in administrators.
JJ, styled as jj, is a band who releases music through the Gothenburg-based independent label Sincerely Yours, which was founded by the Swedish pop group The Tough Alliance.