Athenaeus (/æθɪˈniːəs/; Ancient Greek: Ἀθήναιος) may refer to:

• Athenaeus (officer), an officer of Antigonus I Monophthalmus in the Third War of the Diadochi who led a campaign against the Nabataeans in 312 BC
• Athenaeus, son of Attalus I
• Athenaeus (musician), Greek composer who flourished 128 BC
• Athenaeus Mechanicus, a Peripatetic writer of the 1st century BC, author of On Machines
• Athenaeus of Attalia, physician of the Pneumatist School who practiced at Rome in the 1st century AD
• Athenaeus, of Naucratis in Egypt, Greek rhetorician and grammarian, 2nd and beginning of the 3rd century AD