A governor is a governing official, usually the executive (at least nominally, to different degrees also politically and administratively) of a non-sovereign level of government, ranking under the head of state. In federations, a governor may be the title of each appointed or elected politician who governs a constitutive state.

In some countries the heads of the constitutive states, provinces, communities and regions may be titled "governor," although this is less common in parliamentary systems such as in some European nations and many of their former colonies, which use titles such as President of the Regional Council in France and minister-president in Germany. Other countries using different titles for sub-national units include Spain and Switzerland.

The title also lies, historically, to executive officials acting as representatives of a chartered company which has been granted exercise of sovereignty in a colonial area, such as the British HEIC or the Dutch VOC. These companies operate as a major state within a state with its own armed forces.

There can also be non-political governors: high ranking officials in private or similar governance such as commercial and non-profit management, styled governor(s), who simply govern an institution, such as a corporation or a bank. For example, in the United Kingdom and other Commonwealth countries there are prison governors ("warden" in the United States), school governors and bank governors.

Pre-Roman empires

Though the legal and administrative framework of provinces, each administrated by a governor, was created by the Romans, the term governor has been a convenient term for historians to use in describing similar systems in antiquity. Indeed, many regions of the pre-Roman antiquity were ultimately replaced by Roman 'standardized' provincial governments after their conquest by Rome.

Egypt

• In Pharaonic times, the governors of each of dozens of provinces in the kingdoms of Upper and Lower Egypt (called "nomes" by the Greeks, and whose names often alluded to local patterns of religious worship) are usually known by the Greek word Nomarch.

• The whole (or most) of Egypt was repeatedly reduced to the status of province of a larger empire under foreign conquerors, notably under an Achaemenid satrap (see below).fact: date=June 2008

Pre- and Hellenistic satraps

• Media and Achaemenid Persia introduced the satrapy, probably inspired by the Assyrian / Babylonian examples
• Alexander the Great and equally Hellenistic diadoch kingdoms, mainly Seleucids (greater Syria) and Lagids ('Ptolemies' in Hellenistic Egypt)
• in later Persia, again under Iranian dynasties:
• Parthia
• the Sassanid dynasty dispensed with the office after Shapur I (who had still 7 of them), replacing them with petty vassal rulers, known as shahdars