Title
- Office of the Mother of God1
- Officii et magistrati1
- Omnes ad praeda venient1
- Omnium gentium mores, leges, et ritus1
- On Questions in Aristotle’s Nicomachean Ethics1
- On accounting and commissions1
- On charms and talismans1
- On generation and corruption1
- On mnemonics and memory1
- On perfection and penance1
- On the Anger of God1
- On the martrydom of Ḥusayn1
- Opusculum de formandis epistolis1
- Or ha-sekhel and Sefer ha-Shem1
- Orationes1
- Order1
- Ordinances1
- Oreste e Pylade1
- Organon1
- Orthographia1