Agustín Manuel de Eyzaguirre y Arechavala (Latin American Spanish: [aɣusˈtin ejsaˈɣire]; May 3, 1768 – July 19, 1837) was a Chilean political figure.

During this time he organized the famous Calcutta Company, for direct trade between Valparaíso and the East Indies, and thus was the first that caused the Chilean flag to float in Asiatic seas.

Immediately upon his assuming office he had to deal first with some incidents in Chillán, and then with an insurrection in the island of Chiloé that was trying to break away from the control of the central government and return to the protection of Spain.

This bankruptcy became a big scandal, since the conservative opposition pointed out that the cause was the lack of legal security in a broken down country, while the government countermanded with the fact that the State would have to resume the payment of the foreign debt, when it was already bankrupt itself.

In the midst of this political bickering, colonel Enrique Campino, with the support of the radical federalist group, organized a military coup with the Santiago garrison, dissolving Congress and imprisoning some conservative ministers, chief among them Diego Portales and Manuel José Gandarillas.

On January 25, 1827, he presented his resignation to Congress, which accepted it, and proceeded to name Ramón Freire as Presidente and Francisco Antonio Pinto as Vice President of Chile.