List of national flags by design

A national flag is a one that represents and symbolizes a country or nation-state. Flags – and the related (royal) standards, ensigns, banners, and pennons / pennants – come in many shapes and designs, which often indicate something about what the flag represents, but generally national flags are rectangular or sometimes square-shaped.

Common design elements of flags include shapes as charges – such as crescent moons, crosses, stars, stripes, and suns – layout elements such as including a canton (a rectangle with a distinct design, such as another national flag), and the overall shape of a flag, such as the aspect ratio of a rectangular flag – whether the flag is square or rectangle, and how wide it is – or the choice of a non-rectangular flag. Sometimes these flags are used as a short-hand guide to represent languages on tourist information or versions of websites on the internet.

Many countries with shared history, culture, ethnicity, or religion have similarities in their flags that represent this connection. Sets of flags in this list within the same category may represent countries' shared connections – as with the Scandinavian countries exhibiting the Nordic cross on their flags – or the design similarity may be a coincidence – as with the red and white flags of Indonesia and Monaco and Poland.

For clarity, unless stated, all flags shown are the civil flag ( − the vexillological symbol of identification from FIAV, Fédération internationale des associations vexillologiques) or the national flag () of the nation state / sovereign country recognised as such by the United Nations – the state flags, ( − usually those of the government), along with the flags of autonomous countries, regions, and territories of a UN nation state are annotated in italics as such.

Historical flags are marked with the vexillological symbol and flags that are used widely, but without any legal basis (de facto), are marked with the vexillological symbol.