Navarch (Greek: ναύαρχος; pronounced návarchos) is a Greek word meaning "leader of the ships", which in some states became the title of an office equivalent to that of a modern admiral.
Not all states gave their naval commanders such a title. Athens, for instance, placed its fleet under the command of generals (strategoi) holding the same title as those who commanded its land forces. Such command structures reflected the fact that, especially early in the Classical period, fleets operated in close conjunction with land forces, and indeed, the title of navarch did not begin to appear until the time of the Peloponnesian War, when fleets began to operate more independently. This separate title was originally used in cities that lacked an established naval tradition, Sparta being the most prominent, but entered broader use later, being adopted by the navies of the Hellenistic era states such as Macedon, Syracuse, Ptolemaic and Seleucid Empire, Achaean League, and Rhodes.