Eustathios Maleinos () was a leading Byzantine general and one of the wealthiest and most influential members of the Anatolian military aristocracy during the late 10th century. He held senior administrative and military posts in the East, and was involved in the aristocratic rebellions against Emperor Basil II (r. 976–1025), fighting against Bardas Skleros but supporting the revolt of his nephew Bardas Phokas. After the failure of the latter, he was not punished, but his immense wealth caused his eventual downfall, as Basil II confined him to a mansion in Constantinople and confiscated his wealth after his death.