Eumenes of Cardia (/juːˈmɛniːz/; Greek: Εὐμένης; c. 362 – 316 BC) was a Greek general and scholar. He participated in the Wars of the Diadochi as a supporter of the Macedonian Argead royal house.
He was a native of Cardia in the Thracian Chersonese. At a very early age he was employed as private secretary by Philip II of Macedon, and, after the death of Philip II, by Alexander the Great, whom he accompanied into Asia. After Alexander's death (323 BC), Eumenes took command of a large body of Greek soldiers fighting in support of Alexander's son, Alexander IV. In the ensuing division of the empire, Cappadocia and Paphlagonia were assigned to Eumenes; but as they were not yet subdued, Leonnatus and Antigonus were charged by Perdiccas with securing them for him. Antigonus, however, ignored the order, and Leonnatus vainly attempted to induce Eumenes to accompany him to Europe and share in his far-reaching designs.
Eumenes joined Perdiccas, who installed him in Cappadocia. When Craterus and Antipater, having subdued Greece in the Lamian War, determined to pass into Asia and overthrow the power of Perdiccas, their first blow was aimed at Cappadocia. Craterus and Neoptolemus, satrap of Armenia, were completely defeated by Eumenes in a battle somewhere near the Hellespont in 321 BC. Neoptolemus was killed, and Craterus died of his wounds.