A microstate or ministate is a sovereign state having a very small population or very small land area, but usually both. Some examples include Liechtenstein, Malta, Monaco, Nauru, Singapore, and Vatican City.

The smallest fully sovereign microstate is Vatican City, with 829 citizens as of July 2010 and an area of only 0.44 km².

Microstates should not be confused with micronations, which are not recognized as sovereign states. Special territories without full sovereignty, such as the British Crown Dependencies, The Chinese Special Administrative Regions and overseas territories of Denmark, France, the Netherlands, Norway and the United Kingdom, are also not considered microstates.

Sovereign states with a non-sea area less than 1,000 km² (386 sq mi).

A small number of microstates are founded on historical anomalies or eccentric interpretations of law. These types of microstates are usually located on small (usually disputed) territorial enclaves, generate limited economic activity founded on tourism and philatelic and numismatic sales, and are tolerated or ignored by the nations from which they claim to have seceded.