An ephebe, also written ephebus, is a word used in Ancient Greece to indicate a young male, between the ages of 18 and 20.

It is from the Greek ephbos, meaning "early manhood". The plural is ephebi, and the adjective is ephebic.

A boy becomes an ephebe at age 18, when his period of study is finished, with a festival in his name, put on by his father. He is to cut his hair short, and grow his beard long. He serves an oath to Athens, and spends the next year of his life as a guard, learning to be a soldier. He is then given a spear and a shield, and put on garrison duty in outlying regions. After this last year, he becomes a full citizen under Athenian law.

The purpose of such a time in an Ancient Greek's life was to provide the men with qualities worthy of citizens; robustness, alertness, and modesty - in both thought and action.

There were many statues made of ephebi, being, as they were, such exemplar symbols of youth, skill, and virtue.