| Order: | 105th Doge of the Republic of Genoa |
| Term Start1: | 14 August 1641 |
| Term End1: | 19 June 1642 |
| Predecessor1: | Giovanni Battista Durazzo |
| Successor1: | Giovanni Battista Lercari |
| Birth Date: | 1572 |
| Birth Place: | Genoa, Republic of Genoa |
| Death Date: | 19 June 1642 |
| Death Place: | Genoa, Republic of Genoa |
Giovanni Agostino De Marini (Genoa, 1572 - Genoa, 19 June 1642) was the 105th Doge of the Republic of Genoa and king of Corsica.
On 14 August 1641 De Marini was elected Doge of Genoa, the sixtieth in biennial succession and the one hundred and fifth in republican history. As doge he was also invested with the related biennial office of king of Corsica. Elected probably thanks to the votes of the "new" nobility, which required greater relevance in the European political landscape and a rearmament policy to guarantee the protection of the rivers. He allocated the funds for the construction of twenty galleys and, following the example of the former doge Giacomo Lomellini and Anton Giulio Brignole Sale, he armed one with his money. His political goal was also to improve the relationship between Genoa city and his domain, and therefore he went to Savona to deliver the two galleys prepared by the city. His dogal assignment was interrupted by the illness which after a month, on 19 June 1642, led to his death.[1] [2]