Sir John Cox was an English Royal Navy officer of the seventeenth century.
Cox joined the Navy during the English Republican era, but remained following the Restoration of 1660.
During the Third Anglo-Dutch War, he was given command of HMS Prince, a hundred-gun first-rate ship of the line.
He served as the Duke of York's flag captain during the Battle of Solebay against the Dutch.
The Prince was involved in some of the heaviest fighting, and Cox was killed by an enemy shot while standing close to the Duke.