In Index of Names
- Jacob of Edessa (d. 708) 57, 80–84
- Jambet, Christian 12
- Janos, Damien 566, 585, 589, 610–611, 617
- ¶ Janssens, Jules 191
- Jesus Christ 78, 459, 461, 463–464, 475, 477, 480
- John of Alexandria 472
- John the Grammarian, see John Philoponus
- John Philoponus (d. 574) 32, 40, 45, 47–49, 56–57, 64, 81, 130, 166, 168, 195, 199, 333, 335, 385, 390, 412, 433, 440, 465, 473, 485, 489, 492–493, 495–496, 502, 570, 586–587, 612
- John of Scythopolis (1st half of 6th cent.) 58, 110
- Jonan, periodeutes 79
- Justinian, Roman Emperor (482–565) 108, 112