J1

• AEG J.I, a World War I German ground attack aircraft
• Albatros J.I, a 1917 German ground-attack single-engine biplane aircraft
• Junkers J 1, a 1916 German aircraft
• Junkers J.I, a 1917 German aircraft
• Lawrance J-1, an early 1920s engine used in American aircraft

• LB&SCR J1 class, a British LB&SCR locomotive
• LNER Class J1, a class of British steam locomotives
• PRR J1, an American PRR steam locomotive

• J-I rocket, a Japanese solid rocket expendable launch vehicle
• J1 type submarine, a World War II Imperial Japanese Navy cruiser submarines class
• HMS J1, a 1915 World War I British submarine
• JAC J1, a subcompact car
• Al Fahd 300 (J-1), an Iraqi surface-to-surface missile project

• J-1 World Heavyweight Championship, a professional wrestling competition
• J1 World Tour, a concert tour by Taiwanese singer Jolin Tsai
• J1 Live Concert, a 2005 live album by Taiwanese singer Jolin Tsai
• "J1" (song), a 2008 song by Mallu Magalhães
• J.I the Prince of N.Y, American rapper also known as J.I.

• ATC code J01, Antibacterials for systemic use, a subgroup of the Anatomical Therapeutic Chemical Classification System
• Haplogroup J1 (Y-DNA), a Y-DNA haplogroup
• Janko group J₁, in mathematics
• S/2003 J 1, a former name for Eukelade, a satellite of Jupiter
• First-order Bessel function of the first kind, denoted $j\_1$
• J01, the ICD-10 code for acute sinusitis, a medical condition
• J₁, the Johnson solid notation for an equilateral square pyramid

• J-1 visa, a type of U.S. visa for exchange visitors
• The J1 League, the top division of Japanese association football
• Samsung Galaxy J1, a smartphone
• J1, abbreviation, reference to the director staff of the Joint Chiefs of Staff

• 1J (disambiguation)

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