He is best known for his works:
* "De Regno et Regis Institutione": A treatise on the ideal king and the responsibilities of kingship. It was influential in political thought and was translated into several languages.
* "De Sacra Scriptura": This work focused on biblical interpretation and emphasized the role of reason in understanding scripture.
* "Dialogus de Justa Rei Catholici in Regnum Anglie Successione": This work defended the claim of Mary I of England to the throne against the claims of her Protestant half-sister Elizabeth I.
While less famous, Osorius also authored other works including:
* "De Republica": A book on the nature of the state.
* "De Legibus": A treatise on law.
* "De Bello": A book on warfare.
It's important to note that while he was a humanist, Osorius remained a strong defender of Catholicism. His works often reflect his opposition to Protestant theology.