Author
- Jacob ben David ben Yom Tov1
- Jacob ben Jacob, ha-Kohen, -approximately 12701
- Jacobus de Cessolis1
- Jacopo Ragone1
- Jacopone da Todi1
- Jacques de Vitry1
- James of Viterbo1
- Jehiel ben Jekuthiel ben Benjamin Anav1
- Jewish Community of Pitigliano, Italy1
- Jewish community of unidentified city, Italy1
- Jewish prayers1
- Joannes de Crivelli1
- John Dominici1
- John XXI1
- John XXII1
- John de Breton1
- John de Seccheville1
- Joseph Angelet1
- Joseph Trani1
- Josephus1