French naval commander who engaged British forces during the American Revolution (1775–83).

De Grasse took service in 1734 on the galleys of the Knights of Malta, and in 1740 he entered the French service. Shortly after France and America joined forces in the Revolutionary War, he was dispatched to America as commander of a squadron. In 1779–80 he fought the English off the West Indies. In 1781 he was promoted to the rank of admiral and was successful in defeating Admiral Samuel Hood and in taking Tobago. When American commander George Washington (Washington, George) and the French general the comte de Rochambeau (Rochambeau, Jean-Baptiste-Donatien de Vimeur, comte de) determined to march to Virginia to join forces with the marquis de Lafayette (Lafayette, Marie-Joseph-Paul-Yves-Roch-Gilbert du Motier, marquis de)'s army against the British commander Lord Cornwallis (Cornwallis, Charles Cornwallis, 1st Marquess and 2nd Earl, Viscount Brome, Baron Cornwallis of Eye), Washington requested the cooperation of de Grasse's fleet. De Grasse therefore sailed from the West Indies to the Chesapeake River, where he was joined by a fleet under the comte de Barras. A British force under Admiral Thomas Graves attempted to prevent this juncture by engaging de Grasse's fleet when it arrived at the Chesapeake Bay but was unsuccessful. French naval supremacy in the waters off Yorktown (Yorktown, Siege of) was instrumental in the success of the siege of that city.

After Cornwallis's surrender, de Grasse returned to the West Indies, where he captured the island of St. Kitts in January 1782. In April, however, he was defeated by Admiral George Rodney and taken prisoner. On his return to France, de Grasse published Mémoire du comte de Grasse (1782; “Memoir of the Count of Grasse”) and was acquitted by a court-martial in 1784.