Jabarkan J dari Senarai pemeluk Islam dalam bahasa melayu

Jack Roche - convicted of involvement in an al-Qaeda plot to blow up the Israeli embassy in Canberra.

Jadel Gregório - a Brazilian athlete.

James Achilles Kirkpatrick - was the British Resident in Hyderabad.

Jan Janszoon - Dutch pirate.

Jason Walters - of the Netherlands, member of the Hofstad Network, convicted on charges of terrorism.

Jeff Fort - former Chicago gang leader, co-founder of the Black P. Stones gang, and founder of its El Rukn faction. He was convicted in 1987 of conspiring with Libya to perform acts of domestic terrorism.

Jeffrey Mark Deskovic - served 15-year wrongful imprisonment sentence.

Jemima Goldsmith daughter of the billionaire Sir James, who was married to Imran Khan

Jesse of Kakheti - a ruler of Kakheti in eastern Georgia from 1614 to 1615.

John Allen Muhammad - convicted serial killer, known as the Beltway Sniper.

John Ward - (changed name to Yusuf Reis) British corsair and pirate.

Johann von Leers - advisor to Muhammad Naguib known for his anti-Semitic polemics.<ref>Biographical Dictionary of the Extreme Right Since 1890 edited by Philip Rees, (1991, ISBN 0-13-089301-3)</ref>

José Padilla - the respondent in Rumsfeld v. Padilla currently on trial as an alleged al-Qaida operative, converted while in prison for aggravated assault.

Juan Carlos Gomez - Former Cruiserweight Boxing Champion.