Author
- John Frederick II of Saxony1
- John Gage1
- John Montgomery1
- John Scottowe1
- John de Beauchesne1
- John of Ibelin1
- João Freire1
- João Gomes da Silva1
- Juan Baptista de Gatica1
- Juan Gallo1
- Juan Perez Barahona1
- Juan de Foxá1
- Juan de Mena1
- Juan de Zumárraga1
- Julius III1
- Kamal Khujandi1
- Kamāl al-Dīn ibn Āsāyish Shirwānī1
- Kara Fazlî1
- Keśavamiśra1
- Khalīl ibn Shāhīn1