Giovanni Vasanzio or Jan van Santen (1550–21 August 1621) was a Dutch-born architect, garden designer and engraver who spent his mature career in Rome, where he arrived in the 1580s. Vasanzio was born in Utrecht. He worked as assistant to Flaminio Ponzio and completed works in progress at Ponzio's death (1613); he became in some sense the "house architect' for the Borghese, responsible for ephemeral decorations to provide settings for dynastic events both gay and grave. Vasanzio died in Rome. After his death, Giovanni Battista Soria assumed his role with the Borghese.