Eugenio Necochea (born in Buenos Aires in 1797; died in Santiago de Chile in 1867) was a Chilean soldier.
From his early years, he was deeply interested in the struggle for the independence of Chile, and in 1813 engaged in the campaign of Santa Fé.
In 1817 he formed part of the Army of the Andes as lieutenant of mounted grenadiers under his brother Mariano, and participated in the campaign of Chile until 1820, being promoted major.
In 1824 he obtained leave of absence from the Peruvian army and returned to Buenos Aires, where he remained till 1836.
He was several times a member of the Chamber of Deputies of Chile and provincial elector, and in 1860 was promoted brigadier.