The Battle of the Chesapeake, also known as the Battle of the Virginia Capes or simply the Battle of the Capes, was a crucial naval battle in the American Revolutionary War that took place near the mouth of the Chesapeake Bay on 5 September 1781. The combatants were a British fleet led by Rear Admiral Sir Thomas Graves and a French fleet led by Rear Admiral François Joseph Paul, the Comte de Grasse. The battle was strategically decisive, in that it prevented the Royal Navy from reinforcing or evacuating the besieged forces of Lieutenant General Lord Cornwallis at Yorktown, Virginia. The French were able to achieve control of the sea lanes against the British and provided the Franco-American army with siege artillery and French reinforcements. These proved decisive in the Siege of Yorktown, effectively securing independence for the Thirteen Colonies.

The Chesapeake Bay is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Eastern Shore of Maryland, the Eastern Shore of Virginia, and the state of Delaware. The mouth of the Bay at its southern point is located between Cape Henry and Cape Charles. With its northern portion in Maryland and the southern part in Virginia, the Chesapeake Bay is a very important feature for the ecology and economy of those two states, as well as others surrounding within its watershed. More than 150 major rivers and streams flow into the Bay's 64,299-square-mile (166,534 km2) drainage basin, which covers parts of six states and all of Washington, D.C.