Juan Gutierrez (d. March 1268), also known as "Frontino", was a mercenary and a member of Adieu's Free Company. He, along with Adam Pangratt, Julia Abatemarco and Lorenzo Molla, had previously been imprisoned in Kovir, but was later released by King Esterad Thyssen as one of his so-called "Sly cats" (Polish: "Psotnych kotów"): prisoners offered amnesty and the opportunity for lucrative mercenary work in the aid of the Northern Kingdoms against the Nilfgaardian Empire. This ploy enabled Esterad and the kingdoms of Kovir and Poviss to ostensibly remain politically neutral, whilst in effect actually aiding the North.
After the four were released by Esterad, they left for Redania where they formed the mercenary group known as the Free Company. Alongside the rest of the Free Company, Juan participated in the battles at Mayena and Brenna, but despite his heroic efforts he was killed fighting during the latter.