The Samian War, an Ancient Greek military conflict between Athens and Samos, is initiated by Athens' intervention in a dispute between Samos and Miletus.

When the Samians refuse to break off their attacks on Miletus as ordered, the Athenians easily drive out the oligarchic government of Samos and install a garrison in the city, but the oligarchs soon return, with Persian support.A larger Athenian fleet is dispatched to suppress this agitation.

This fleet initially defeats the Samians and blockaded the city, but Pericles, in command, is then forced to lead a substantial portion of the fleet away upon learning that the Persian fleet is approaching from the south.

Although the Persians turn back before the two fleets meet, the absence of most of the Athenian fleet allows the Samians to drive off the remaining blockaders and, for two weeks, control the sea around their island; upon Pericles' return, however, the Athenians again blockade and besiege Samos; the city surrenders nine months later.

Under the terms of the surrender, the Samians tear down their walls, give up hostages, surrender their fleet, and agree to pay Athens a war indemnity over the next 26 years.During the course of the war, the Samians had apparently appealed to Sparta for assistance; the Spartans were initially inclined to grant this request, and were prevented from doing so primarily by Corinth's unwillingness to participate in a war against Athens at the time.

In 433 BCE, when Corcyra requests Athenian assistance against Corinth, the Corinthians will remind the Athenians of the good will they had shown at this time.