| Order: | 142nd Doge of the Republic of Genoa |
| Term Start1: | 22 September 1713 |
| Term End1: | 22 September 1715 |
| Predecessor1: | Francesco Maria Imperiale |
| Successor1: | Lorenzo Centurione |
| Birth Date: | 1607 |
| Birth Place: | Madrid, Spanish Empire |
| Death Date: | 1672 |
| Death Place: | Genoa, Republic of Genoa |
Giovanni Antonio Giustiniani (Madrid, 1676 - Genoa, 1735) was the 142nd Doge of the Republic of Genoa and king of Corsica.
Member of the noble Giustiniani family, he was born in Madrid around 1676. The elections of 22 September 1713 elected him new doge of the Republic of Genoa, the ninety-seventh in biennial succession and the one hundred and forty-second in republican history. As doge he was also invested with the related biennial office of king of Corsica. Giustiniani ended his term on 22 September 1715 and died in Genoa in 1735.[1]