Anastasius Germonius (also Anastase Germon) (1551 – 4 August 1627) was an Italian Canon lawyer, diplomatist and archbishop of Tarantaise, who belonged to the family of the marquises of Ceve, in Piedmont, where he was born.
As archdeacon at Turin he was a member of the commission appointed by Pope Clement VIII to edit the Liber Septimus decretalium (later known as the Constitutiones Clementinae); and he also wrote Paratitla on the five books of the Decretals of Gregory IX. He represented the Duke of Savoy at the court of Rome under Clement VIII and Paul V, and was ambassador to Spain under Kings Philip III and IV.
Germonius is best known for his treatise on ambassadors, De legatis principum et populorum libri tres (Rome, 1627). According to the Encyclopædia Britannica Eleventh Edition, "[t]he book is diffuse, pedantic and somewhat heavy in style, but valuable historically as written by a theorist who was also an expert man of affairs."