The exact number of countries in the world is highly disputed. This gallery is based at root on the discontinued CIA World Factbook's list of 192 "sovereign entities". It does not include autonomous regions or internal "countries". Only countries whose national flag has a legally recognised or de facto construction guideline have been included. In the cases of Afghanistan and Albania, publicly available laws only specify the imposition of a design over a background and give the proportions of said design. In the case of Barbados, this is based on an artist's interpretation.

The inclusion or lackthereof of a flag does not reflect any personal political or religious beliefs.