Author
- Jacob Berab1
- Jacob ben Asher1
- Jacob ben Jacob, ha-Kohen, -approximately 12701
- Jacob ibn Habib1
- Jacobus de Voragine1
- James of Lausanne1
- Jerome1
- Joachim Heinrich Campe1
- John of Seville ?1
- Joseph Nasi1
- Joseph ben Abraham Gikatilla1
- Joseph ben Gorion1
- Joseph ben Judah ibn Aknin1
- Joshua ben Israel Benveniste1
- Joshua ibn Shuaib1
- Judah Leib Prossnitz1
- Leo I1
- Leon Pace Ginesi1
- Leon of Modena1
- Leʼon di Belentish1