Milesia, Milesian, Milesians, or Miletans may refer to:

• Milesians (Irish), a people figuring in Irish mythology
• Milesians (Greek), the inhabitants of Miletus, a city in the Anatolia province of modern-day Turkey
• Milesian school, a school of thought founded in the 6th century BC and exemplified by three philosophers from Miletus
• Milesian tale, a genre of salacious or exotic narrative
• Milesia (fly), a genus of very large hoverflies