Author
- John of Saxony1
- John of Seville ?1
- John of Wales1
- John Dokeianos1
- John, Duke of Berry1
- Joseph Albaradani1
- Joseph Haslewood1
- Joseph Nasi1
- Joseph Trani1
- Joseph ben Judah ibn Aknin1
- Joseph ben Moses Sarfati1
- Joseph ibn Abitur1
- Joseph ibn Migash1
- Joshua Benzion Segre1
- José Antonio de Alzate y Ramírez1
- João Freire1
- João Gomes da Silva1
- Juan Félix de Rújula1
- Juan Gallo1
- Juan Martínez Silíceo1