A state flag is a flag that is used by a government to represent that nation.

The flag flown by government and on diplomatic missions overseas. It often consists of the national flag with the addition of the country's coat-of-arms or emblem. Most countries do not have a separate state flag.

is the flag flown by the government of a country, distinguished from the civil flag, used by the citizenry, and from military flags. Where they differ from civil flags, state flags often carry a coat of arms, and possession of a state flag is likely to be forbidden except to government authorities. the official flag of the country used by the government; perhaps government flag would be clearer. As opposed to the flag used by the people or the military (see civil, war and national flag, below). A state ensign is a flag used at sea by government ships. Where they differ from civil flags, state flags often carry a coat of arms. in the U.S., Mexico, Australia, and some other countries which have sub-national units called "states", the state flag may also refer to them.

The version of the national flag for use by a country's government.

There are two separate meanings for the term state flag in vexillology - the flag of state of a government, and the flag of an individual subnational state.