- J ... jacaranda
- Jacaranda cuspidifolia ... Jackson, Abraham Valentine Williams
- Jackson, Al, Jr. ... Jacksonville
- Jacksonville ... Jacobus de Voragine
- Jacoby, Larry L. ... Jaggaiah, Kongara
- Jaggar, Alison ... Jakab Ferencné
- Jakab Zsuzsanna ... Jamaican fruit bat
- Jamaican pepper ... James, Harry
- James, Harry Haag ... Jamuka
- Jamuna ... János vitéz
- János Zápolya ... Japanese
- Japanese allspice ... Japanese spaniel
- Japanese spider crab ... Jarrell, Randall
- Jarres, Plain des ... Jaumann, Gustav Andreas Johannes
- Jaunde ... Jay Leno Show, The
- Jay Leno’s Garage ... Je tu il elle
- Je vous salue, Marie ... Jefferson
- Jefferson ... Jellyfish Eyes
- Jelnik ... Jenny
- Jenny Jones ... Jersey Law
- Jersey Lily, The ... Jesus Only
- Jesus Prayer ... jewelers’ borax
- Jewell, Edward Alden ... Jhering, Rudolf von
- Jherria ... Jicaque language
- Jicarilla Apache ... Jimmy Carter National Historic Site
- Jimmy Choo, Ltd. ... Jinpingmei
- jinrickshaw ... JNR
- Jo Jo Dancer, Your Life Is Calling ... Jobson, Eddie
- Jobst ... Johannes Damascenus
- Johannes de Bado Aureo ... John Frederick
- John Frederick II ... John of Ibelin
- John of Jandun ... John XXI
- John XXII ... Johnson, Celia
- Johnson, Chad ... Johnson, Reverdy
- Johnson, Rian ... joint implementation
- Joint Industrial Council ... Jomhūrī-ye Eslāmī-ye Afghānestān
- Jomhūrī-ye Eslāmī-ye Īrān ... Jones, Franklin
- Jones, Gareth ... Jones, Vaughan Frederick Randal
- Jones, William ... Jorge Blanco, Salvador
- Jorge de Montemor ... Josephson sisters
- Josephson, Brian D. ... Journal de la liberté de la presse, Le
- Journal de Liouville ... Jovian planet
- Jovii dynasty ... Juan Fernandez fur seal
- Juan Fernández Islands ... Judas Iscariot
- Judas Maccabaeus ... Judicial Powers Construed
- judicial restraint ... Juilliard, Augustus D.
- Juin, Alphonse ... Juliet, Naked
- Juliet, Naked ... jumping pit viper
- jumping plant louse ... Jungle Book
- Jungle Book, The ... Jupiter Optimus Maximus, Temple of
- Jupiter Symphony ... just compensation
- Just Dance ... Justowriter
- Justus ... Jyväskylä
