Giovanni Battista Vanni (c. 1599 – 27 July 1660) was an Italian painter and engraver of the Baroque period.
Vanni was born in either Pisa or Florence around 1599; he studied successively under Jacopo da Empoli, Aurelio Lomi, and Matteo Rosselli, and then became a disciple of Cristofano Allori.
In 1642, he etched a series of fifteen plates from Correggio's frescoes from the cupola of Parma Cathedral which depict the Assumption of the Virgin (1526–30).
His works include a Triumph of David, now in the palace of the Alberti in Prato, an Annunciation for the church of San Francesco di Paola in Florence and a Saint Sebastian Healed at the Feet of the Virgin for the church of San Giovanni dei Fiorentini in Rome.
He frescoed a Meal in the house of the Pharisee for a refectory attached to the Church of Santa Maria del Carmine, Florence.