Agesilaus II was a Eurypontid king of Sparta who reigned from approximately 400 to 360 BCE. His rule was dominated by military efforts to preserve Spartan dominance in Greece. He initially led a campaign against Persia in Asia Minor but was recalled to fight in the Corinthian War, where he secured a victory at the Battle of Coronea in 394 BCE.

The latter part of his career was defined by the struggle against the rising power of Thebes. This conflict culminated in the decisive Spartan defeat at the Battle of Leuctra in 371 BCE. Agesilaus subsequently helped organize the defense of Sparta itself during the Theban invasion of Laconia. He died around 360 BCE while returning from a mercenary expedition to Egypt, which was undertaken to replenish Sparta's depleted finances.

Agesilaus II is not known to have authored any surviving written works. The principal historical sources for his life and reign are the contemporary writings of Xenophon, particularly the Hellenica and the encomium Agesilaus.

His lengthy reign represents a critical period in Spartan history, marking the transition from its supremacy after the Peloponnesian War to a rapid decline triggered by Theban ascendancy. His career illustrates the limits of Spartan power, the inherent difficulties of maintaining hegemony over Greece, and the strategic priorities of Sparta in the early fourth century BCE.