Gianantonio Davia (13 October 1660 – 11 January 1740) was an Italian prelate of the Catholic Church, who served as an apostolic nuncio, Bishop/Archbishop, cardinal, and secretary of a major department (congregration) of the Roman Curia.

Davia was born in Bologna to a prominent family, whose name is also spelled as D'Avia and De Via.

He was educated in both canon and civil law at the University of Bologna, and early in life, served as a magistrate and a soldier in the war between Venice and the Ottomans in 1684, where he took part in the siege of Santa Maura.

In 1727, he was named Protector of Scotland, and minister of England to the exiled of Stuart pretender in Rome in April 1728.

In 1725 Cardinal Davia donated to the Academy of Sciences of the Institute of Bologna a pendulum regulator of fine quality, a Newtonian reflecting telescope, and a quadrant.