Giovanni Stefano Donghi (1608 – November 1669) was an Italian Catholic cardinal.
He was born in Genoa in 1608, the son of Bartolomeo Donghi and Giacoma Bernardi. After completing his undergraduate work in the Humanities and Philosophy, he began his university studies at the University of Bologna and completed them with a degree from the University of Salamanca.
Donghi was created a cardinal-deacon by Pope Urban VIII in the consistory of 13 July 1643, and assigned the Deaconry of San Giorgio in Velabro on 31 August 1644. Urban died a year later, on 29 July 1644, and – as Evelyn notes – Donghi was one of the fifty-seven cardinals who participated in the papal conclave of 1644. The Conclave opened on 9 August, and resulted in the election of Pope Innocent X on 15 September 1544. Donghi was openly a part of the Spanish faction of the College of Cardinals.